Vitamin D

Does Vitamin D Prevent Depression?

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Why You Can’t Believe Everything You Read

depressionThe days are getting shorter and Seasonal Depression, often called the “winter blues”, will soon be upon us. Most of the research on Seasonal Depression has centered on the effect of sunlight on our hormones.

However, sunlight is also responsible for the synthesis of vitamin D in our skin cells. So, some experts have hypothesized that low levels of 25-hydroxyvitamin D, the active form of vitamin D, in our blood also play a role in the winter blues.

If so, that could have important implications for managing depression, especially in older adults. Depression is estimated to affect around 6.5 million of the 49 million adults over the age of 65 in our country. Treatment costs for older adults in this country are estimated at $9 billion/year.

If something as simple and inexpensive as a vitamin D supplement could reduce the risk of depression, it would be a huge boon to our health care system.

Association studies suggest that may be a possibility. For example, one recent meta-analysis of 6 clinical studies (H Li et al, The American Journal of Geriatric Psychiatry, 27: P1192-1202, 2019) reported that every 10 ng/mL increase in 25-hydroxyvitamin D was associated with a 12% decrease in the risk of depression in older adults.

However, association studies do not prove cause and effect.

Unfortunately, randomized, placebo controlled clinical trials have given mixed results. A few studies suggested that vitamin D might reduce depression risk, but most of the studies found no effect of vitamin D on depression risk. However, most of the published studies have been poorly designed They were too small, too short, or did not use validated methods for measuring depression.

This was the genesis of the current study (OI Okerke et al., JAMA, 324: 471-480, 2020). It was designed to be a definitive study that would avoid the defects of previous studies.

The study concluded that vitamin D supplementation does not decrease the risk of depression in older adults, and those were the headlines you have probably seen. But is that conclusion true? Let’s take a peek behind the curtain and analyze the study.

How Was The Study Done?

Clinical StudyThis study was an offshoot of the VITAL (VITamin D and OmegaA-3 TriaL) clinical study, so let me start by describing the characteristics of that study.

The VITAL study (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403) enrolled 25,871 healthy adults (average age = 67) in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had preexisting cancer or heart disease.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 65% of the participants to determine 25-hydroxyvitamin D levels (a measure of vitamin D status) at baseline and at the end of the first year to assess the effectiveness of vitamin D supplementation. The participants were given either 2,000 IU of vitamin D/day or a placebo and followed for an average of 5.3 years.

This study consisted of 18,353 participants from the VITAL study. Ninety percent of the participants had no previous history of depression. Ten percent had previously been diagnosed or treated for depression but had been depression-free for over 2 years.

The participants filled out annual questionnaires to quantify the onset of depression by three criteria:

  • A diagnosis of depression by a physician.
  • Treatment for depression (medications, counseling, or both).
  • A questionnaire designed to evaluate symptoms of depression. The authors of the study referred to this as an assessment of their mood.

During the 5.3 year follow up period 3.6% of the participants reported the onset of diagnosed depression or a mood consistent with depression. This is consistent with previous studies showing that 1-5% of healthy, non-institutionalized older adults suffer from depression.

Does Vitamin D Prevent Depression?

thumbs down symbolThe results of the study were clear.

Treatment with 2,000 IU of vitamin D3 compared to placebo for 5.3 years did not have a statistically significant effect on:

  • The incidence or recurrence of depression diagnosis, or…
  • Treatment for depression, or…
  • Clinically relevant depressive symptoms.

The authors concluded, “These findings do not support the use of vitamin D3 in adults to prevent depression.”

Why You Can’t Believe Everything You Read

It would be tempting to say, “Case closed. We now know for certain that vitamin D has no effect on depression.”

After all, this was an excellent study. It was large (18,353 participants), lasted a long time (5.3 years), and used well established measures of depression. What’s not to like?

Peek Behind The CurtainUnfortunately, even well-designed studies can give misleading results. Let’s take a peek behind the curtain and see where this study went astray.

There were two glaring deficiencies in this study.

#1: Most of the participants had adequate vitamin D status at the beginning of the study. The average 25-hydroxyvitamin D level of participants at the beginning of the study was 31 ng/mL (78 nmol/L). The NIH considers 20-50 ng/mL (50-125 nmol/L) to be an adequate level of 25-hydroxyvitamin D for most physiological functions. This means that study participants started in the middle of the adequate range with respect to vitamin D status.

This was not a failure of study design. In fact, the authors of the study are to be commended for measuring the vitamin D status of participants at the beginning of the study. Many previous studies have neglected to do that.

The problem is that vitamin D has become extremely popular. Many Americans are already taking multivitamins or vitamin D supplements. To recruit enough people for the study the authors were forced to allow participants to enter the study even if they were taking vitamin D supplements, as long as the amount did not exceed 800 IU/day.

In short, most of the participants in this study were already supplementing with up to 800 IU/day of vitamin D. If so, they were allowed to continue taking their vitamin D supplements. The 2,000 IU of vitamin D was added to what they were already taking.

The question then becomes, if people are already taking RDA levels of supplemental vitamin D and their blood levels of 25-hydroxyvitamin D are already in the adequate range, do we really expect additional supplemental vitamin D to have a beneficial effect?

The author’s answer to that question was, “The mean baseline 25-hydroxyvitamin D level was 30.8 ng/mL; this value is already at a threshold for extraskeletal health benefits [health benefits other than bone health], and so the ability to observe effects of vitamin D3 supplementation may have been attenuated. [To determine whether vitamin D supplementation reduces the risk of depression] large-scale studies would be required to address the effects of high-dose, long-term vitamin D3 supplementation among those with nutrient deficiency.”

My more direct answer would be, “This study provides no useful information on whether vitamin D3 supplementation reduces the risk of depression. What is needed are studies that start with a population that is deficient in vitamin D.”

An accurate conclusion from this study would have been, “If you are already taking vitamin D supplements and/or have an adequate vitamin D status, supplementation with an extra 2,000 IU of vitamin D3 provides no additional benefit with respect to the risk of developing depression.” But that is not what the headlines said.

#2: The study did not record the reason for the onset of depression. That is important because the top 3 causes of depression in adults 65 and older are:

  • Loss of a spouse or partner.
  • Chronic health issues.
  • Restricted blood flow to the brain.

It is unlikely that vitamin D supplementation would have much of an effect on these issues.

In contrast, seasonal depression, which is more likely to be affected by vitamin D supplementation, was not measured in this study.

The Bottom Line

You may have seen recent headlines saying that vitamin D supplementation has no effect on the risk of developing depression.

The study behind these headlines was a very well-designed study. It was large (18,353 participants), lasted a long time (5.3 years), and used well established measures of depression.

It would be tempting to say, “Case closed. We now know for certain that vitamin D supplementation has no effect on depression.”

Unfortunately, even well-designed studies can give misleading results. This one had a major flaw that made the data almost useless.

The problem is that most Americans are already taking multivitamins or vitamin D supplements. To recruit enough people for the study the authors were forced to allow participants to enter the study even if they were taking vitamin D supplements, as long as the amount did not exceed 800 IU/day.

That meant that most participants already had adequate blood levels of 25-hydroxyvitamin D at the beginning of the study.

The question then becomes, if people are already taking RDA levels of supplemental vitamin D and their blood levels of 25-hydroxyvitamin D are already in the adequate range, do we really expect additional supplemental vitamin D to have a beneficial effect? The answer is, “Probably not”.

Rather than saying that this study definitively shows that vitamin D supplementation has no effect on the risk of developing depression, I feel it would be more accurate to say, “This study provides no useful information on whether vitamin D3 supplementation reduces the risk of depression. What is needed are studies that start with a population that is deficient in vitamin D.”

An accurate conclusion from this study would have been, “If you are already taking vitamin D supplements and/or have an adequate vitamin D status, supplementation with an extra 2,000 IU of vitamin D3 provides no additional benefit with respect to the risk of developing depression.” But that is not what the headlines said.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

The Truth About Vitamin D And Respiratory Diseases

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How Should You Prepare For This Winter?

deadSome health experts are making dire predictions for this fall when COVID-19 overlaps with our annual flu season. People are worried.

When people are worried, hucksters smell a quick buck and start coming out of the woodworks. They are touting all sorts of miracle pills and potions that will keep us safe this winter. The FDA is doing its best to shut them down, but it’s like the “Whack A Mole” game you may remember from the county fair. As soon as the FDA shuts one down, another pops up.

In the meantime, you are left trying to sort through the claims. I could write a whole book on the truth (and lies) about the claims you are seeing on the internet. But this week I will focus on vitamin D. I will give you unbiased answers to three questions.

1) What is the truth about vitamin D and respiratory disease?

2) Will vitamin D help protect you against COVID-19?

3) How should you prepare for this winter?

I am basing today’s “Health Tip” on a recently published study (H Brenner et al, Nutrients 2020, 12, 2488) looking at the effect of vitamin D status on deaths from respiratory disease in older German adults.

How Was The Study Done?

Clinical StudyThe data from this study were taken from an ongoing study in Germany looking at the effect of diet and lifestyle on health outcomes in older adults. In this case, 9548 adults, ages 50-75, from the region of Saarland in Germany were enrolled in the study between 2000 and 2002 and followed for an average of 15 years.

Blood samples were drawn at the time of enrollment and 25-hydroxyvitamin D levels were determined as a measure of vitamin D status. Deaths and cause of deaths over the 15 year period were obtain from German health records.

The basic characteristics of the study population were:

  • The gender breakdown was 43.8% men, 52.6% female.
  • The average age was 62.1 years.
  • Almost all participants were Caucasians of German or French descent.
  • 8% were vitamin D insufficient (25-hydroxyvitamin D of 30-<50 nmol/L)
  • 1% were vitamin D deficient (25-hydroxyvitamin D of <30 nmol/L)

Note: Almost 60% of this study group had an inadequate vitamin D status. The comparable figures for the US population are 42% with inadequate vitamin D status (34% vitamin D insufficient and 8% vitamin D deficient).

The reasons for this are likely two-fold:

  • Saarland is at the latitude of Newfoundland, Canada, so sun exposure is less than for most Americans.
  • Germans are less likely to consume supplements than Americans.

However, the fact that 60% of this study group has inadequate vitamin D status makes it a particularly good group to look at the effect of vitamin D status on health outcomes.

The Truth About Vitamin D And Respiratory Diseases

the truth signThis study found:

  • Vitamin D insufficiency (25-hydroxyvitamin D of 30-<50 nmol/L) increased the risk of dying from respiratory disease by 1.9-fold for men and 2.1-fold for women.
  • Vitamin D deficiency (25-hydroxyvitamin D of <30 nmol/L) increased the risk of dying from respiratory disease by 2.3-fold for men and 3.0-fold for women.

The authors pointed out that this was consistent with a recent meta-analysis of randomized clinical trials showing that supplementation with RDA levels of vitamin D reduced the risk of acute respiratory tract infections by 70% in people who were vitamin D deficient.

The authors concluded:

“Vitamin D insufficiency and deficiency are common and account for a large proportion of respiratory disease mortality in older adults…Our results, along with evidence from meta-analyses from RCTs [Randomized Placebo-Controlled Clinical Trials] regarding results of vitamin D3 supplementation on various outcomes, suggest that vitamin D3 supplementation could contribute to lowering mortality from respiratory and other diseases during and beyond the COVID-19 pandemic, particularly among women.”

How Should You Prepare For This Winter?

Winter WindNow it is time to answer the three questions I posed at the beginning of this article:

1) What is the truth about vitamin D and respiratory disease?

There have been many studies suggesting that inadequate vitamin D status increases the risk of “catching” respiratory diseases such as the seasonal flu. Some of those studies showed that supplementation with vitamin D3 reduced the risk of catching respiratory diseases. However, most of those were small studies.

This study and the meta-analysis the authors referred to were much larger, better designed studies. Other large, well designed studies are needed. But, taken together, these two studies strongly support the hypothesis that inadequate vitamin D status significantly increases the risk of developing and dying from respiratory diseases.

However, we do need to put this into perspective.

  • Supplementation with vitamin D primarily protects individuals with inadequate vitamin D status. It doesn’t appear to offer significant benefit for individuals with adequate vitamin D status (>50 nmol/L 25-hydroxyvitamin D).
  • Supplementation with vitamin D at doses of 2,000 IU or less appears to be sufficient for most people. There is little evidence that megadoses are beneficial unless you are severely vitamin D deficient (more about that below).

2) Will vitamin D help protect you against COVID-19?

vitamin dThe answer to this question is less clear. As we learn more about COVID-19 we have learned that it is much more than just a respiratory disease. On the other hand, cellular studies suggest that vitamin D may interfere with the mechanism by which COVID-19 attacks cells.

What do clinical studies say? We are just learning. Four small clinical trials and one large study have recently been published or posted online as preprints prior to being accepted for publication.

  • The second study (HW Kaufman et al, PLOS One, September 17, 2020) used data from a major national testing center (Quest Diagnostics) and linked COVID-19 test results with 25-hydroxyvitamin D test results for 191,779 patients. This study reported that vitamin D deficiency was associated with a 30% increased risk of testing positive for COVID-19.
  • The third study found that vitamin D deficiency was associated with hospital admissions for COVID-19.
  • The fourth study found that vitamin D deficiency was associated ICU admissions for COVID-19.

Taken together these 5 studies suggest that vitamin D deficiency may increase the risk of being infected by COVID-19 and on the severity of the disease if you are infected.

I should point out that these studies are preliminary. Normally we would say that they need to be confirmed by larger studies before becoming incorporated into the standard of care for COVID-19.

You might be saying to yourself, , “Why is the medical community paying so much attention to preliminary studies?” The answer is simple:

  • The need is urgent. We need all the tools at our disposal to fight this deadly disease, and we need them now.
  • Vitamin D3 supplementation at 2,000 IU or less is inexpensive and safe. Plus, even if further studies find that our vitamin D status has no effect on COVID-19 risk, we know that adequate vitamin D has many other potential health benefits.

To summarize:

  • Preliminary studies suggest that adequate vitamin D status may offer some protection for COVID-19. These studies are not definitive. No reputable scientist is ready to tell you that vitamin D will ward off COVID-19. However, supplementation with 2000 IU/day or less of vitamin D3 is safe and may have multiple health benefits.
  • Vitamin D should not be considered a “magic bullet”. It is just one aspect of a holistic approach to creating a healthy body that is less susceptible to respiratory diseases like COVID-19.

3) How Should You Prepare For This Winter?

Winter WindAs we approach the winter months, the days are getting shorter and sun exposure is decreasing. This is the time of year when your 25-hydroxyvitamin D levels will be at their lowest.

At the same time, we are likely to see a convergence of the seasonal flu, flu-like illnesses, and COVID-19 this winter. You will need a healthy body, a healthy immune system, and adequate vitamin D status more than ever.

When asked about vitamin D and COVID-19 in a recent interview, Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, said, “If you’re deficient in vitamin D, that does have an impact on your susceptibility to infection. I would not mind recommending, and I do it myself, taking vitamin D supplements.”

I recommend supplementation with vitamin D3 to make sure your vitamin D status is adequate. The RDA for vitamin D is 600 IU for adults and 800 IU for seniors over the age of 70. However, because the efficiency with which we convert vitamin D3 to 25-hydroxyvitamin D varies from person to person, many experts recommend supplementing with 1,500-2,000 IU of vitamin D3.

I also recommend that you ask your health provider for a 25-hydroxyvitamin D test. If you are in the vitamin D deficient range, your health provider may recommend more than 2,000 IU/day of vitamin D3.

Finally, we should not rely on vitamin D alone. As I discussed in a previous issue of “Health Tips From The Professor”, I recommend a holistic approach for strengthening our immune systems, and I recommend the CDC guidelines for reducing the risk of catching both the flu and COVID-19.

I would note that social distancing, hand washing, and mask wearing are just as effective at reducing the risk of getting the flu as they are for getting COVID-19. In fact, some Asian countries practice mask wearing in public every flu season.

The Bottom Line

  • A recent study found that inadequate vitamin D status caused a 2-3-fold increased risk of dying from respiratory illnesses for seniors (ages 50-74).
  • A previous meta-analysis reported that supplementation with RDA levels of vitamin D reduced the risk of acute respiratory tract infections by 70% in people who were vitamin D deficient.
  • Taken together, these two studies strongly support the hypothesis that inadequate vitamin D status significantly increases the risk of developing and dying from respiratory diseases.
  • Preliminary studies suggest that adequate vitamin D status may offer some protection for COVID-19. These studies are not definitive. No reputable scientist is ready to tell you that vitamin D will ward off COVID-19. However, supplementation with 2000 IU/day or less of vitamin D3 is safe and may have multiple health benefits.
  • Vitamin D should not be considered a “magic bullet”. It just one aspect of a holistic approach to creating a healthy body that is less susceptible to respiratory diseases like COVID-19.

So, how should we prepare for this winter?

  • As we approach the winter months, the days are getting shorter and sun exposure is decreasing. This is the time of year when your 25-hydroxyvitamin D levels will be at their lowest.
  • At the same time, we are likely to see a convergence of the seasonal flu, flu-like illnesses, and COVID-19 this winter. You will need a healthy body, a healthy immune system, and adequate vitamin D status more than ever.
  • I recommend supplementation with vitamin D3 to make sure your vitamin D status is adequate. The RDA for vitamin D is 600 IU for adults and 800 IU for seniors over the age of 70. However, because the efficiency with which we convert vitamin D3 to 25-hydroxyvitamin D varies from person to person, many experts recommend supplementing with 1,500-2,000 IU of vitamin D3.
  • Finally, we should not rely on vitamin D alone. As I discussed in a previous issue of “Health Tips From The Professor”, I recommend a holistic approach for strengthening our immune systems, and I recommend the CDC guidelines for reducing the risk of catching both the flu and COVID-19.

I would note that social distancing, hand washing, and mask wearing are just as effective at reducing the risk of getting the flu as they are for getting COVID-19. In fact, some Asian countries practice mask wearing in public every flu season.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Poverty Affect Nutritional Status?

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How Can We Improve Nutrition In Disadvantaged Communities?

Calcium FoodsRecently there has been increased focus on health disparities in disadvantaged communities. In our discussions of the cause of these health disparities, two questions seem to be ignored.

1. Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

The study (K Marshall et al, PLoS One 15(7):e0235042) I discuss in this week’s “Health Tips From The Professor” attempts to address both of these questions.

Before, I start, let me put this study into context.

  • Osteoporosis is a major health problem in this country. Over 2 million osteoporosis-related fractures occur each year, and they cost our health care system over 19 billion dollars a year. Even worse, for many Americans these osteoporosis-related fractures often cause:
    • A permanent reduction in quality of life.
    • Immobility, which can lead to premature death.
  • Inadequate calcium and vitamin D intakes increase the risk of osteoporosis.

While most studies simply report calcium and vitamin D intakes for the general population, this study breaks them down according to ethnicity and income levels. The results were revealing.

How Was The Study Done?

Clinical StudyThis study drew on data from the 2007-2010 and 2013-2014 National Health and Nutrition Examination Surveys (NHANES). These surveys are conducted by the National Center for Health Statistics, which is part of the CDC. They are designed to assess the health and nutritional status of adults and children in the United States and are used to produce health statistics for the nation.

The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by highly trained medical personnel. All participants visit a physician. Dietary interviews and body measurements are included for everyone.

This study measured calcium intake, vitamin D intake, and osteoporosis for adults 50 and older. The data were separated by gender, ethnic group and income level. Four different measures of poverty were used. For purposes of simplicity, I will only use one of them, income beneath $20,000, for this article.

Does Poverty Affect Nutritional Status?

The Effect of Ethnicity And Gender On Calcium And Vitamin D Intake: 

FriendsWhen the authors looked at the effect of ethnicity and gender on calcium and vitamin D intake, in people aged 50 and older the results were (Note: I am using the same ethnic nomenclature used in the article):

Hispanics:

    • 66% (75% for women and 56% for men) were getting inadequate calcium intake.
    • 47% (47% for women and 47% for men) were getting inadequate vitamin D intake.

Non-Hispanic Blacks:

    • 75% (83% for women and 64% for men) were getting inadequate calcium intake.
    • 53% (51% for women and 54% for men) were getting inadequate vitamin D intake.

Non-Hispanic Whites:

    • 60% (64% for women and 49% for men) were getting inadequate calcium intake.
    • 33% (30% for women and 37% for men) were getting inadequate vitamin D intake.

For simplicity, we can generalize these data by saying:

Gender:

    • Women are more likely to be calcium-deficient than men.
    • Men are more likely to be vitamin D-deficient than women.

Ethnicity: For both genders and for both calcium and vitamin D:

    • The rank order for deficiency is Non-Hispanic Blacks > Hispanics > Non-Hispanic Whites.

The Effect Of Poverty On Calcium Intake, Vitamin D Intake, And Osteoporosis:

PovertyWhen looking at the effect of poverty, the authors asked to what extent poverty (defined as income below $20,000/year) increased the risk of calcium and vitamin D deficiency in adults over 50. Here is a summary of the data

Hispanics:

    • For both Hispanic women and Hispanic men, poverty had little effect on the risk of calcium and vitamin D deficiency.

Non-Hispanic Blacks:

    • For Non-Hispanic Black women, poverty had little effect on the risk of calcium deficiency, and vitamin D deficiency.
    • For Non-Hispanic Black men, poverty increased the risk of both calcium and vitamin D deficiency by 32%.

Non-Hispanic Whites:

    • For Non-Hispanic White women, poverty had little effect on the risk of calcium deficiency but increased the risk of vitamin D deficiency by 30%.
    • For Non-Hispanic White men, poverty increased the risk of both calcium deficiency and vitamin D deficiency by 18%.

For simplicity, we can generalize these data by saying:

    • Poverty increased the risk of both calcium and vitamin D deficiency for Non-Hispanic Black men, Non-Hispanic White women, and Non-Hispanic White men.

Other statistics of interest:

  • The SNAP program (formerly known as Food Stamps) had little effect on calcium and vitamin D intake. There are probably two reasons for this:
    • In the words of the authors, “While the SNAP program has been shown to decrease levels of food insecurity, the quality of the food consumed by SNAP participants does not meet the standards for a healthy diet.” In other words, the SNAP program ensures that participants have enough to eat, but SNAP participants are just as likely to prefer junk and convenience foods as the rest of the American population. The SNAP program provides no incentive to eat healthy foods.
    • We also need to remember that dairy foods are a major source of calcium and vitamin D in the American diet and that Hispanics and Non-Hispanic Blacks are more likely to be lactose-intolerant than the rest of the American population. There are other sources of calcium and vitamin D in the American diet. But without some nutrition education, most Americans are unaware of what they are.
  • An increased risk of osteoporosis was found in Non-Hispanic Black men, and Non-Hispanic Whites with incomes below $20,000/year.
    • This increased risk of osteoporosis was seen primarily for the individuals in each group who were deficient in calcium and vitamin D. There were other factors involved, but I will focus primarily on the effect of poverty on calcium and vitamin D intake in the discussion below.

How Can We Improve Nutrition In Disadvantaged Communities?

Questioning WomanLet’s start with the two questions I posed at the beginning of this article:

1. Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

In terms of calcium intake, vitamin D intake, and the risk of osteoporosis, the answer to both questions appears to be, “Yes”. So, the question becomes, “What can we do?”

It is when we start to ask what we can do to increase calcium and vitamin D intake and decreased the risk of osteoporosis in disadvantaged communities that we realize the complexity of the problem. There are no easy answers. Let’s look at some of the possibilities.

[Note: I am focusing on what we can do to prevent osteoporosis, not to detect or treat osteoporosis. The solutions for those issues would be slightly different.]

1. We could increase funding for SNAP. That would increase the quantity of food available for low income families, but, as noted above, would do little to improve the quality of the food eaten.

2. We could improve access to health care in disadvantaged communities. But unless physicians started asking their patients what they eat and start recommending a calcium and vitamin D supplement when appropriate, this would also have little impact on diet quality.

3. We could improve nutrition education. A colleague of mine in the UNC School of Public Health ran a successful program of nutrition education through churches and community centers in disadvantaged communities for many years. The program taught people how to eat healthy on a limited budget. Her program improved the health of many people in disadvantaged communities.

However, the program was funded through grants. When she retired, federal and state money to support the program eventually dried up. The program she started is a model for what we should be doing.

4. The authors suggested food fortification as a solution. In essence, they were suggesting that junk and convenience foods be fortified with calcium and vitamin D. That might help, but I don’t think it is a good idea.

If we want to improve the overall health of disadvantaged communities, we need to find ways to replace junk and convenience foods with healthier foods. Adding a few extra nutrients to unhealthy foods does not make them healthy.

5. The authors also said that a calcium and vitamin D supplement would be a cheap and convenient way to eliminate calcium and vitamin D deficiencies. Unfortunately, supplements are currently not included in the SNAP program. Unless that is changed, even inexpensive supplements are a difficult choice for families below the poverty line.

As I said at the beginning of this section, there are no easy answers. It is easy to identify the problem. It would be easy to throw money at the problem. But finding workable solutions that could make a real difference are hard to identify.

Yes, we should make sure every American has enough to eat. Yes, we should make sure every American has access to health care. But, if we really want to improve the health of our disadvantaged communities, we also need to:

  • Change the focus of our health care system from treatment of disease to prevention of disease.
  • Train doctors to ask their patients what they eat and to instruct their patients how simple changes in diet could dramatically improve their health.
  • Provide basic nutrition education to disadvantaged communities at places where they gather, like churches and community centers. This would cover topics like eating healthy, shopping healthy on a limited budget, and cooking healthy.

We don’t necessarily need another massive federal program. But those of us with the knowledge could each volunteer to share that knowledge in disadvantaged communities.

  • Cover basic supplements, like multivitamins, calcium and vitamin D supplements, and omega-3 supplements in food assistance programs like SNAP.

The Bottom Line

Osteoporosis is a major health problem in this country. Over 2 million osteoporosis-related fractures occur each year, and they cost our health care system over 19 billion dollars a year. Even worse, for many Americans these osteoporosis-related fractures often cause:

  • A permanent reduction in quality of life.
  • Immobility, which can lead to premature death.

We know that inadequate calcium and vitamin D intakes increase the risk of osteoporosis. But most studies simply report calcium and vitamin D intakes for the general population. At the beginning of this article, I posed two questions.

  1.  Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

A recent study looked at the effect of gender, ethnicity and income levels on calcium intake, vitamin D intake, and the risk of developing osteoporosis. The results of this study shed some light on those two questions.

When looking at the effect of gender and ethnicity on the risk of inadequate calcium and vitamin D intake, the study found:

  • Women are more likely to be calcium-deficient than men.
  • Men are more likely to be vitamin D-deficient than women.
  • For both genders and for both calcium and vitamin D, the rank order for deficiency is Non-Hispanic Blacks > Hispanics > Non-Hispanic Whites. [Note: Note: I am using the same ethnic nomenclature used in the study.]
  • Poverty (defined as incomes below $25,000/year) significantly increased the risk of both calcium and vitamin D deficiency for Non-Hispanic Black men, Non-Hispanic White women, and Non-Hispanic White men.
  • An increased risk of osteoporosis was also found in Non-Hispanic Black men, and Non-Hispanic White men and women with incomes below $20,000/year.
  • This increased risk of osteoporosis was seen primarily for the individuals in each group who were deficient in calcium and vitamin D.

In short, this study suggests that the answer to both questions I posed at the beginning of the article is, “Yes”.

For more information and a discussion of what we could do to correct this health disparity in disadvantaged communities, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Vitamin D Prevent Type 1 Diabetes?

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Does Genetics Influence Supplementation Benefits?

diabetesThe cause of type 1 diabetes is a mystery. If you go to an authoritarian source like the Mayo Clinic, you will discover that:

  • Type 1 diabetes is an autoimmune disease that selectively attacks the insulin-producing islet cells of the pancreas.
  • Certain genetic variants predispose individuals to type 1 diabetes.
  • The autoimmune response may be triggered by a viral infection or other unknown environmental factors in genetically susceptible individuals.
  • The incidence of type 1 diabetes increases as you travel away from the equator, which suggests that vitamin D may be involved.

The idea that vitamin D may be involved is an important concept because it suggests that vitamin D supplementation might reduce the risk of developing type 1 diabetes. This idea was reinforced by a Finnish study (E Hyponnen et al, Lancet, 358: 1500-1503, 2001) published in 2001 showing the vitamin D supplementation of newborn infants reduced the incidence of type 1 diabetes at age 1.

However, subsequent studies in other parts of the world have had mixed results. Some have confirmed the results of the Finnish study. Others have come up empty.

Similarly, some studies have shown a correlation between low 25-hydroxyvitamin D levels in the blood and the development of type 1 diabetes in children, while other studies have found no correlation.

Why the discrepancy between studies? Some of the differences can be explained by differences in the populations studied or differences in study design. But what if there were another variable that none of the previous studies has considered?

The study (JM Norris et al, Diabetes, 67: 146-154, 2018) I review this week describes just such a variable. The authors of the study hypothesized that the association between 25-hydroxyvitamin D levels and the risk of developing type 1 diabetes is influenced by mutations that affect the way vitamin D works in the body. Previous studies have not taken these mutations into account. If the author’s hypothesis is true, it might explain why these studies have produced conflicting results.

In this article, I will answer 3 questions:

  • Does vitamin D prevent type 1 diabetes?
  • If so, is supplementation with vitamin D important?
  • Who will benefit most from vitamin D supplementation?

But, before I answer those questions, I should begin by providing some background. I will start by reviewing the how diet, increased need, disease, and genetics influence the likelihood that we will benefit from supplementation. Then I will review vitamin D metabolism.

Does Genetics Influence Supplementation Benefits?

need for supplementsThe reason so many studies find no benefit from supplementation is that they are asking the wrong question. They are asking “Does supplementation benefit everyone?” That is an unrealistic expectation.

I have proposed a much more realistic model (shown on the left) for when we should expect supplementation to be beneficial. Simply put, we should ask:

  • Is the diet inadequate with respect to the nutrient that is being studied?
  • Is there an increased need for that nutrient because of age, gender, activity level, or environment?
  • Is there a genetic mutation that affects the metabolism or need for that nutrient?
  • Is there an underlying disease state that affects the need for that nutrient?

When clinical studies are designed without taking this paradigm into account, they are doomed to fail. Let me give you some specific examples.

  • The Heart Outcomes Prevention Evaluation study concluded supplementation with folate and other B vitamins did not reduce heart disease risk. The problem was that 70% of the people in the study were getting adequate amounts of folate from their diet at the beginning of the study. For those individuals not getting enough folate in their diet, B vitamin supplementation decreased their risk of heart disease by 15%. This is an example of poor diet influencing the need for supplementation.

The other three examples come from studies on the effect of vitamin E supplementation on heart disease that I summarized in an article in “Health Tips From The Professor” a few years ago. Here is a brief synopsis.

  • The Women’s Health Study concluded that vitamin E did not decrease heart disease risk in the general population. However, the study also found that in women over 65 (who are at high risk of heart disease), vitamin E supplementation decreased major cardiovascular events and cardiovascular deaths by 25%. This is an example of increased need because of age and gender influencing the need for supplementation.
  • The Women’s Antioxidant Cardiovascular Study” concluded that vitamin E did not decrease heart disease risk in the general population. However, when they looked at women who already had cardiovascular disease at the beginning of the study, vitamin E supplementation decreased risk of heart attack, stroke, and cardiovascular death by 23%. This is an example of an underlying disease affecting the need for supplementation.
  • The HOPE study concluded that vitamin E did not decrease heart disease risk in the general population. However, when they looked at individuals with a mutation that increases the risk of heart disease, vitamin E supplementation significantly decreased their risk of developing heart disease. This is an example of genetics affecting the need for supplementation.

These are just a few of many examples. When you ask whether supplementation benefits everyone, the answer is often no. However, when you look at people with inadequate diet, increased need, underlying disease, and/or genetic predisposition, the answer is often yes.

This background sets the stage for the current study. Of course, to understand the author’s hypothesis that mutations in genes involved in vitamin D metabolism might influence the effect of vitamin D on the risk of developing type 1 diabetes, you need to know a little about vitamin D metabolism.

Biochemistry 101: Vitamin D Metabolism

Vitamin D MetabolismWhen sunlight strikes a metabolite of cholesterol in our skin, it is converted to a precursor that spontaneously isomerizes to form vitamin D3. Because this series of reactions is usually not sufficient to provide all the vitamin D3 our bodies require, we also need to get vitamin D3 from diet and supplementation.

However, vitamin D3 is not active by itself. It first needs to be converted to 25-hydroxyvitamin D by our liver and then to the active 1,25-dihydroxyvitamin D. 1,25-dihydroxyvitamin D is an important hormone that regulates many cells in our body.

Some of the 1,25-dihydroxyvitamin D is synthesized by our kidneys and released into the bloodstream. This 1,25-dihyroxyvitamin D binds to vitamin D receptors on the surface of many cells and initiates regulatory pathways that affect metabolism inside the cell.

Other cells take up 25-hydroxyvitamin D and convert it to 1,25-dihydroxyvitamin D themselves. In these cells both the synthesis and regulatory effects of 1,25-dihydroxyvitamin D occur entirely inside the cell.

In both cases, it is 1,25-dihydroxyvitamin D that regulates cellular metabolism. The only difference is the way this regulation is accomplished.

There are two additional points that are relevant to this study.

  • The efficiency of conversion of vitamin D to 25-hydroxyvitamin D varies from person to person.
    • Thus, blood levels of 25-hydroxyvitamin D are considered a more reliable measure of vitamin D status than dietary intake of vitamin D or sun exposure.
    • Blood levels of 25-hydroxyvitamin D levels ≥50 nmol/L are considered optimal, while levels of 30 to <50 nmol/L are considered suboptimal, and levels <30 nmol/L are considered deficient.
  • 1,25-dihydroxyvitamin D binds to the vitamin D receptor on immune cells. This initiates a series of reactions that decrease the risk of autoimmune responses by our immune system.

How Was This Study Done?

Clinical StudyThis study was called TEDDY (The Environmental Determinants Of Type 1 Diabetes in the Young). Between September 2004 and February 2010, 424,788 newborn infants from 6 medical centers in Colorado, Georgia, Washington, Finland, Germany, and Sweden were screened for genes that predispose to type 1 diabetes.

The investigators identified 21,589 high-risk infants, and 8,676 of them were enrolled in this study before age 4 months. Clinic visits for the children occurred every 3 months between 3 and 48 months of age and every 6 months thereafter.

  • A DNA sample was taken at the time they entered the study and analyzed for mutations in genes involved in vitamin D metabolism.
  • 25-hydroxy vitamin D levels were obtained at each office visit. Because some studies have suggested the vitamin D status during the first year of life is important, the data were analyzed in two ways.
    1. An average of all 25-hydroxyvitamin D levels (referred to as “childhood 25-hydroxyvitamin D levels”).
    1. An average of 25-hydroxyvitamin D levels during the first 12 months (referred to as “early infancy 25-hydroxyvitamin D levels”).
  • Serum autoantibodies to pancreatic islet cells were measured at each office visit as a measure of an autoimmune attack on those cells. Persistent autoimmune response was defined as positive autoantibodies on two consecutive office visits.

While this study did not directly measure type 1 diabetes, children with an autoimmune response to their pancreatic islet cells are highly likely to develop type 1 diabetes. Thus, for purposes of simplicity I will refer to “risk of developing type 1 diabetes” rather than “persistent autoimmune response” in describing these results.

    1. 418 children developed persistent autoantibodies to their pancreatic islet cells during the study. The onset of this autoimmune response ranged from 2 months to 72 months with an average of 21 months.
    1. These children were compared to 3 matched controls from their medical center who did not develop an autoimmune response.

This study was remarkable for two reasons:

1) It was much larger than previous studies. This gave it greater power to detect an effect of vitamin D status on the risk of developing type 1 diabetes.

2) This was the first study to ask whether mutations in genes controlling the metabolism of vitamin D influenced the effect of vitamin D on the risk of developing type 1 diabetes.

Does Vitamin D Prevent Type 1 Diabetes?

Vitamin DThe study compared the risk of developing type 1 diabetes in children whose 25-hydroxyvitamin D levels were optimal (≥50 nmol/L) to children whose 25-hydroxyvitamin D levels were suboptimal (30 to <50 nmol/L). The results were:

  • Optimal vitamin D status during childhood was associated with a 31% decrease in the risk of developing type 1 diabetes.
  • Optimal vitamin D status during early infancy (first 12 months) was associated with a 40% decrease in the risk of developing type 1 diabetes.

In other words, having optimal vitamin D status significantly reduces the likelihood of developing of type 1 diabetes in childhood.

  • 25-hydroxyvitamin D levels >75 nmol/L provided no additional benefit.

In other words, you need sufficient vitamin D, but higher levels provide no additional benefit.

  • They tested 5 genes involved in vitamin D metabolism to see if they influenced the effect of vitamin D on the risk of developing type 1 diabetes. Only the VDR (vitamin D receptor) gene had any influence.
    • When the VDR gene was fully functional, optimal vitamin D status had no effect on the risk of developing type 1 diabetes. This means that even suboptimal (30 to <50 nmol/L) levels of 25-hydroxyvitamin D were sufficient to prevent type 1 diabetes when the vitamin D receptor was fully functional.
    • Only 9% of the children in this study were vitamin D deficient (<30 nmol/L 25-hydroxyvitamin D). Presumably, these children would be at high risk of developing type 1 diabetes even with a fully functional VDR gene. However, there were not enough children in that category to test this hypothesis.
  • When they looked at children with mutations in the VDR gene:
    • Optimal vitamin D status during childhood was associated with a 59% decrease in the risk of developing type 1 diabetes.
    • Optimal vitamin D status during early infancy (first 12 months) was associated with a 67% decrease in the risk of developing type 1 diabetes.

In short, the need for optimal vitamin D levels to reduce the risk of developing type 1 diabetes is only seen in children with a mutation in the VDR (vitamin D receptor) gene.

  • This is a clear example of genetics affecting the need for a nutrient.
    • For children with a fully functional VDR gene, even 30-50 nmol/L 25-hydroxyvitamin D was sufficient to reduce the risk of developing type 1 diabetes.
    • However, children with mutations in the VDR gene required ≥50 nmol/L 25-hydroxyvitamin D to reduce their risk of developing type 1 diabetes.
  • This is also an example of genetics affecting the need for supplementation with vitamin D.
    • 42% of the children in this study had suboptimal levels of 25-hydroxyvitamin D. Those who also have a mutation in the VDR gene would require supplementation to bring their 25-hydroxyvitamin D up to the optimal level to reduce their risk of developing type 1 diabetes.
    • Other studies have estimated that up to 61% of children in the US may have suboptimal 25-hydroxyvitamin D levels.

What Does This Study Mean For You?

Questioning WomanLet’s start with the three questions I proposed at the beginning of this article.

1) Does vitamin D prevent type 1 diabetes? Based on this study, the answer appears to be a clear yes. However, this is the first study of this kind. We need more studies that into account the effect of mutations in the VDR gene.

2) If so, is supplementation with vitamin D important? If we think in terms of supplementation with RDA levels of vitamin D or sufficient vitamin D to bring 25-hydroxyvitamin D into the optimal range, the answer is also a clear yes. However, there is no evidence from this study that higher doses of vitamin D provide additional benefits.

3) Who will benefit most from vitamin D supplementation? Based on this study, the children who will benefit the most from vitamin D supplementation are those who have a suboptimal vitamin D status and have a mutation in the VDR (vitamin D receptor) gene. To put this into perspective:

    • Up to 60% of children and adults in this country have suboptimal vitamin D levels.
    • The percentage of suboptimal vitamin D levels is highest for people who are obese, have pigmented skin, are institutionalized (eg, elderly in nursing homes), and/or live far from the equator.
    • Supplementation with a multivitamin containing the RDA for vitamin D reduces the risk of having suboptimal vitamin D status by 2.5 to 5-fold depending on the person’s ethnicity.
    • This study may be just the tip of the iceberg. The vitamin D receptor is also found on many other cells that control important biological functions.

Finally, if you are a parent or parent-to-be, you probably have several questions. Here are the ones I have New Parentsanticipated:

#1: Is my child at risk for developing type 1 diabetes? If you or a close family member has type 1 diabetes, you can assume your child is genetically predisposed to developing type 1 diabetes. Other factors that increase your child’s risk of developing type 1 diabetes are obesity, non-White ethnicity, and geographical location far from the equator.

#2: Should I have my baby tested for genetic predisposition to type 1 diabetes? That is not currently recommended. Just be aware of the risk factors listed above.

#3: Should I have my baby tested for VDR mutations? That is unnecessary. If your child has a VDR mutation, they just need sufficient vitamin D, not mega doses of vitamin D. And there are lots of other reasons for making sure your child gets sufficient vitamin D.

#4: How much vitamin D should my child be getting? The recommendation is 400 IU up to age 1 and 600 IU over age 1.

#5: Should I give my child vitamin D supplements? It is a good idea. For children over age 1, I recommend a multivitamin supplying 600 IU of vitamin D.

For infants, the American Association of Pediatrics recommends 400 IU vitamin D drops, regardless of whether the infants are breast or formula fed. That is because studies during the first year of life show that less than one-fifth of all infants get the recommended 400 IU/d from any source, and fewer than one out of 10 breast-fed infants meet the requirement – even if the mother is getting adequate vitamin D in their diet.

One Caution: I do not recommend exceeding 400 IU for infants or 600 IU for children unless directed by your health care provider. In terms of the risk of developing type 1 diabetes, your child needs sufficient vitamin D, and more is not better.

#6: Should I have my child tested for 25-hydroxyvitamin D levels? That is not done routinely at the present time. However, if your child has one or more of the risk factors listed above, it is a conversation you should have with your health care provider.

The Bottom Line

While it is widely accepted that vitamin D helps reduce the risk of developing type 1 diabetes in childhood, that has been difficult to prove. Clinical studies have provided conflicting results. The authors of a recent study postulated that the discrepancies between studies may have arisen because the studies neglected the effect of mutations in genes controlling vitamin D metabolism which may affect the ability of vitamin D to reduce the risk of developing type 1 diabetes.

This study found that:

1) Infants and children with optimal vitamin D status (25-hydroxyvitamin D levels ≥50 nmol/L) were 31-40% less likely to develop type 1 diabetes than children with suboptimal vitamin D status (25-hydroxyvitamin D = 30 to <50 nmol/L).

2) However, the effect of vitamin D on the risk of developing type 1 diabetes was only seen in children with one or more mutations in the VDR (vitamin D receptor) gene. To interpret this observation, you need to know that:

    • Type 1 diabetes is caused by an autoimmune attack on the pancreatic islet cells that release insulin.
    • 1,25-dihydroxyvitamin D promotes immune tolerance and decreases the risk of autoimmune responses.
    • 1,25-dihydroxyvitamin D exerts this effect by binding to the vitamin D receptor on the surface of immune cells.

3) Thus, mutations in the VDR gene modify the effect of vitamin D on the risk of developing type 1 diabetes. Specifically:

    • When the VDR gene is fully active, even suboptimal levels of vitamin D appear to be sufficient to prevent the development of type 1 diabetes in childhood.
    • However, when the VDR gene has mutations that reduce its activity, suboptimal levels of vitamin D no longer prevent type 1 diabetes. Optimal levels of vitamin D are required to reduce the risk of developing type 1 diabetes.

This is an example of genetics increasing the need for a nutrient (vitamin D) and increasing the need for supplementation to make sure that optimal levels of that nutrient are achieved.

While this study focused on the effect of vitamin D on the development of type 1 diabetes, this may just be the tip of the iceberg. The vitamin D receptor is also found on many other cells that control important biological functions.

For more details, read the article above. You will probably want to read the section “What Does This Mean For You?”, including my recommendations for parents of young children

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Preparing For The New Normal

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Can Supplements Strengthen My Immune System?

COVID-19The United States and the rest of the world are facing the biggest challenge of our lifetimes. COVID-19 has killed hundreds of thousands of people and decimated economies around the world.

As of the publication date of this article we have no vaccine and only one treatment option that appears to be about 30% effective in a preliminary clinical trial. People are scared.

The question I get asked most often is: “Can supplements protect me from COVID-19”. That’s not a question I can answer with confidence. The few studies we have are small and preliminary. Plus, there is too much we still do not know about COVID-19.

However, there are studies about how diet and supplements affect the immune system. I can answer the question, “Can Supplements Strengthen My Immune System”, with confidence. That will be the focus of this article.

However, before covering that, let me take an objective look at what our “New Normal” will be like and how we can prepare for it.

Preparing For The New Normal

ProfessorAs a scientist I am appalled by the divisive and hyper-partisan arguments about how we should be handling the COVID-19 pandemic. This is a time when our country should be united against a common enemy. Instead I see myths and lies propagated on both sides of this important issue.

The press only magnifies the problem by repeating the myths without fact checking. Whether they are on the left or the right, the media only repeats myths that fit their narrative. As a result, people like you are confused and scared.

Let me try to give you a more objective and scientific view of what the “New Normal” will look like, and how we can prepare for it.

Let’s start with one of the biggest arguments over the past few weeks – when should we reopen our country. This argument is based on the myth that if we wait long enough, the virus will be gone, and life can return to normal.

Nothing could be further from the truth. In reality viruses don’t work that way. They continue to circulate through the population at low levels. Whenever we emerge from our homes and resume our daily lives, the virus will be lurking. There will be flare-ups. There will be hot spots. There will be deaths. And the press will report every one.

So, the question should not be when we emerge. It should be how we emerge. We should emerge cautiously. We should continue to take appropriate precautions. These precautions will become our “New Normal” until we have an effective vaccine. By now, you probably have the CDC precautions memorized, but let me repeat them here:

  • If you are sick, stay home until you recover. If your symptoms worsen, contact your doctor right away.
  • If you are exposed, get tested right away and self-quarantine for 14 days if you test positive.
  • When you go out, wear a face mask and practice social distancing. When you get home, wash your hands in soap and water for 20”.
  • For now, we will need to avoid the customary handshake (and if you are from the South like me, the customary hug).
  • If you are very old or very sick, you should stay home as much as possible. If you have a loved one in this category, you should do everything in your power to protect them from exposure.
  • The guideline that is hardest to project into the future is the one on crowd size. It is hard to predict what the CDC will recommend about crowd size as part of our “New Normal” a few months from now. However, because this virus is extremely contagious, it may be risky to attend any gatherings where there are large, tightly packed crowds for the foreseeable future. This could include some of our favorite things – like movies, live theater, night clubs, and sporting events.Myth Versus Facts

Finally, there is another big myth, namely that the virus will simply disappear once we have a vaccine. Vaccines reduce your risk of exposure because fewer people are carriers of the virus. However, coronaviruses never disappear. They continue to circulate in the population for decades.

Even after we have a vaccine, people will still get sick from COVID-19. People will still die from COVID-19. The difference is that we will no longer hear about COVID-19 cases and deaths on the nightly news. Those cases and deaths will just become part of the statistics that the CDC collects on flu-like illnesses each year – and everyone ignores.

Now that I have discussed what the “New Normal” will look like and summarized the CDC guidelines for reducing your exposure to COVID-19 as the lockdown eases, let me add another guideline of my own:

  • Keep your immune system as strong as possible.

Why Is Keeping Your Immune System Strong Important?

strong immune systemIt is no secret that the media likes to focus on bad news. It is the bad news that draws people in and keeps them coming back for more.

Pandemics are no different. It doesn’t matter whether we are talking about the Spanish flu, SARS, MERS, or COVID-19. We focus on cases and deaths – the bad news. We ignore the good news – there are millions of people who were infected and had no symptoms.

However, if you have been listening closely to what the experts have been saying rather than relying on the media for your information, the good news is obvious.

  • 80-85% of people who have tested positive for COVID-19 have mild or moderate symptoms. Their symptoms are no worse than they experience with the seasonal flu.
  • Preliminary antibody tests suggest that the number of people infected with COVID-19 who experience no symptoms may be 10 to 40 times higher than reported cases.
  • The experts say that the difference is a strong immune system. They tell us that it is people with weakened immune systems that suffer and die from COVID-19.

So, how do you keep your immune system strong? Let’s start by looking at the role of supplementation.

Can Supplements Strengthen My Immune System?

MultivitaminsThose of you who follow me know that I consider supplementation as just one aspect of a holistic approach to health. However, I am starting with supplements because the question I am often asked these days is: “Can supplements protect me from COVID-19”.

As I said at the beginning of this article, that is not a question I can answer with confidence. Instead, the question you should be asking is, “Can Supplements Strengthen My Immune System?”

As I mentioned above, the experts are telling us that it is people with weakened immune systems who suffer and die from COVID-19. That means it is important to keep our immune system as strong as possible.

How do we do that? Here is what an international group of experts said in a recent review (PC Calder et al, Nutrients, 12, 1181-1200, 2020).

1) “A wealth of mechanistic and clinical data show that vitamins A, B6, B12, C, D, E, and folate; trace elements zinc, iron, selenium, magnesium, and copper; and omega-3 fatty acids EPA and DHA play important and complementary roles in supporting the immune system.”

2) “Inadequate intake and status of these nutrients are widespread, leading to a decrease in resistance to infections, and an increase in disease burden.”

They then made the following recommendations:

1) Supplementation with the above micronutrients and omega-3 fatty acids is a safe, effective, and low-cost strategy to help support optimal immune function.

    • They recommended 100% of the RDA for vitamins A, B6, B12, C, D, E, and folate and minerals zinc, iron, selenium, magnesium, and copper in addition to the consumption of a well-balanced diet.
    • They recommended 250 mg/day of EPA + DHA.

2) Supplementation above the RDA for vitamins C and D is warranted.

    • They recommend 200 mg/day of vitamin C for healthy individuals and 1-2 g/day for individuals who are sick.
    • They recommend 2000 IU/day (50 ug/day) for vitamin D.

3) Public health officials are encouraged to include nutritional strategies in their recommendations to improve public health.

Their recommendations could be met by a multivitamin that provides all the micronutrients they recommend, an omega-3 supplement, and extra vitamins C and D.

What Else Should I Do To Strengthen My Immune System?

healthy foodsAs I said above, supplementation is only one part of a holistic approach to a strong immune system. Here are the other components of a holistic approach:

1) It starts with a healthy diet.

    • Eat foods from all 5 food groups.
    • Eat plenty of fruits and vegetables. They provide antioxidants and phytonutrients that are important for our immune system.
    • Eat plenty of high fiber foods. Include whole grains and beans in addition to fruits and vegetables. That’s because the friendly gut bacteria that strengthen our immune system need a variety of fibers from different food sources to feed on.
    • Eat oily fish on a regular basis.
    • Avoid sodas, sugary foods, and highly processed foods.
    • Avoid high fat diets

2) Get adequate sleep. For most of us, that means 7-8 hours of sleep a night.

3) Maintain a healthy weight.

4) Get adequate exercise. Aim for a minimum of 150 minutes of moderate intensity exercise each week.

5) Manage stress and anxiety in healthy ways. Yes, that means if you let the news about COVID-19 cause anxiety, you are weakening your immune system. You may want to turn off the news and try prayer, meditation, yoga, or whatever relieves stress for you.

The Bottom Line

In this article, I summarized the “New Normal” we face as we emerge from lockdown and how to navigate the new normal as safely as possible. If I were to summarize this article in a few short sentences, this is what I would say:

Until we have an effective vaccine the “New Normal” is a world in which a dangerous virus is lurking in the community, waiting to strike the unprepared.

Forget all the angry rhetoric about when we should emerge from lockdown. The important question is not when we emerge. It is how we emerge.

We don’t need to stay huddled in our homes, fearful to leave, unless we are very old or very sick.

We do need to take appropriate precautions when we leave home based on the recommendations of the CDC. None of us are invincible as far as this virus is concerned. More importantly, if we bring the virus home, we may kill the very people we love the most. We need to follow the guidelines.

We should also make sure that our immune system is as strong as possible through a holistic combination of diet, supplementation, adequate sleep, exercise, weight management, and stress reduction.

For more information on CDC COVID-19 Guidelines, click here.

For more details about preparing for the new normal and diet & supplementation recommendations, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Vitamin D Affect Muscle Strength?

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Why Is Vitamin D Research So Controversial?

vitamin dMost people lose muscle strength as they age, something called sarcopenia. This is not a trivial matter. Loss of muscle mass:

  • Leads to loss of mobility. It can also make it difficult to do simple things like lifting your grandchild or carrying a bag of groceries.
  • Increases your risk of falling. This often leads to serious fracture which increases your of dying prematurely. In fact, bone fractures increase your risk of dying by 3-fold or more. Even in those who recover their mobility and quality of life may never be the same.
  • Lowers your metabolic rate. This increases your risk of obesity and all the diseases that are associated with obesity.

Loss of muscle strength as we age is preventable. There are several things we can do to preserve muscle strength as we age, but in today’s article I will focus on the effect of vitamin D on muscle strength.

What if something as simple as preventing vitamin D deficiency could improve muscle strength as we age? That idea has been around for a decade or more. But, for reasons I will detail below, it has proven controversial. Let me start by sharing the latest study on vitamin D and muscle strength (N Aspell et al, Clinical Investigations in Ageing, volume 2019:14, pages 1751-1761).

How Was The Study Done?

Clinical StudyThe data for this study came from 4157 adults who were enrolled in the English Longitudinal Study On Aging. Participants in this study were all over the age of 60 and were still living in their own homes. The general characteristics of the study population were:

  • Their average age was 69.8 with 45% male and 55% female.
  • While 76% of the participants rated their health as “good” or above
    • 73% were overweight or obese.
    • 54% had a longstanding disease that limited mobility.
    • 29% were taking multiple medications.

Serum 25-hydroxy vitamin D levels were determined as a measure of vitamin D status.

  • 22% of the participants were vitamin D deficient (<30 nmol/L 25-hydroxy vitamin D).
  • 34% of the participants were vitamin D insufficient (between 30 and 50 nmol/L 25-hydroxy vitamin D).
  • 46% of the participants had adequate vitamin D status (>50 nmol/L 25-hydroxy vitamin D).

Muscle strength was assessed by a handgrip strength test with the dominant hand. Muscle performance was assessed with something called the short physical performance battery (SPPB), consisting of a walking speed test, a repeated chair raise test, and a balance test.

Does Vitamin D Affect Muscle Strength?

When the data on handgrip strength were analyzed:

  • Only 22% of the participants who had adequate vitamin D status had low handgrip strength.
  • 40% of participants who were vitamin D deficient had low handgrip strength. That’s almost a 2-fold difference.
  • Handgrip strength increased linearly with vitamin D status.
    • The relationship between vitamin D status and handgrip strength was highly significant (p<001).
    • The beneficial effect of vitamin D status on handgrip strength plateaued at around 55-69 nmol/L 25-hydroxy vitamin D. In other words, you need adequate vitamin D status to support muscle strength, but higher levels provide no additional benefit.

When the data on muscle performance (the SPPB test) were analyzed:

  • Only 8% of the participants who had adequate vitamin D status scored low on this test.
  • 25% of participants who were vitamin D deficient scored low on this test. That’s a 3-fold difference.
  • Muscle performance also increased linearly with vitamin D status.
    • The relationship between vitamin D status and muscle performance was also highly significant (p<001).
    • The beneficial effect of vitamin D status on muscle performance also plateaued at around 55-69 nmol/L 25-hydroxy vitamin D.

The authors concluded: “Vitamin D deficiency was associated with impaired muscle strength and performance in a large study of community-dwelling older people. It is generally accepted that vitamin D deficiency should be reversed to prevent bone disease. This strategy may also protect skeletal muscle function in aging.”

Why Is Vitamin D Research So Controversial?

ArgumentYou can be forgiven if you are saying to yourself: “I’ve heard this sort of thing before. I see a blog or headline claiming that vitamin D has a certain benefit, but it’s usually followed by later headlines saying those claims are false. Why can’t the experts agree? Is all vitamin D research bogus?”

The relationship between vitamin D status and muscle strength is no different.

  • Most, but not all, studies looking at the association between vitamin D status and muscle strength find that vitamin D status affects muscle strength.
  • However, many randomized, placebo-controlled clinical trials looking at the effect of vitamin D supplementation on muscle strength have come up empty.

A meta-analysis (L Rejnmark, Therapeutic Advances in Chronic Disease, 2: 25-37, 2011) of randomized, placebo-controlled clinical trials of vitamin D supplementation and muscle strength provides insight as to why so many of them come up empty.

The meta-analysis combined data from 16 clinical trials. The conclusions were similar to what other meta-analyses have found:

  • Seven of the studies showed a benefit of vitamin D supplementation on muscle strength. Nine did not.
  • When the data from all 16 studies were combined, there was only a slight beneficial effect of vitamin D supplementation on muscle strength.

However, it was in the discussion that the reason for these discrepancies became apparent. There were three major deficiencies in study design that were responsible for the discrepancies.

1) There was a huge difference in study design.

    • The subjects were of different ages, genders, and ethnicities.
    • The dose of vitamin D supplementation varied.
    • Different measures of muscle strength and performance were used.

Until the scientific and medical community agree on a standardized study design it will be difficult to obtain consistent results.

While this deficiency explains the variation in outcomes from study to study, there are two other deficiencies in Garbage In Garbage Outstudy design that explain why many of the studies failed to find an effect of vitamin D on muscle strength. I call this “Garbage In, Garbage Out”. Simply put, if the study has design flaws, it may be incapable of detecting a positive effect of vitamin D on muscle strength.

2) Many of the studies did not measure vitamin D status of the participants at the beginning of the study.

    • The results of the study described above show that additional vitamin D will be of little benefit for anyone who starts the study with an adequate vitamin D status.
    • In the study above 46% of the participants had adequate vitamin D status. This is typical for the elderly community. When almost 50% of the participants in a study have adequate vitamin D status at the beginning of a study it becomes almost impossible to demonstrate a beneficial effect of vitamin D supplementation on any outcome.

It is essential that future studies of vitamin D supplementation start with participants who have low vitamin D status. Otherwise, you are almost guaranteeing a negative outcome.

3) Most of the studies ignored the fact that vitamin D status is only one of three factors that are essential for muscle strength.

    • In the case of muscle strength, especially in the elderly, the three essentials are vitamin D, protein, and exercise. All three are needed to maintain or increase muscle strength. Simply put, if one is missing, the other two will have little or no effect on muscle strength. Unfortunately, you cannot assume that exercise and protein intake are adequate in older Americans:
      • Many older adults don’t get enough exercise because of physical limitations.

Unfortunately, many clinical studies on the effect of vitamin D supplementation and muscle strength fail to include exercise and adequate protein intake in the study. Such clinical trials are doomed to failure.

Now you know why vitamin D research is so controversial. Until the scientific and medical community get their act together and perform better designed experiments, vitamin D research will continue to be controversial and confusing.

What Does This Mean For You?

Old Man Lifting WeightsLoss of muscle mass as we age is not a trivial matter. As described above, it:

  • Leads to loss of mobility.
  • Increases your risk of falling. This often leads to serious fracture which increase your risk of disability and death.
  • Lowers your metabolic rate, which increases your risk of obesity and obesity-related diseases.

So, what can you do prevent loss of muscle mass as you age? The answer is simple:

1) Aim for 25-30 grams of high-quality protein in each meal.

    • That protein can come from meat, fish, eggs, or legumes.
    • That doesn’t mean you need to consume an 8-ounce steak or a half chicken. 3-4 ounces is plenty.
    • However, it does mean you can’t subsist on green salads and leafy greens alone. They are healthy, but you need to include a good protein source if you are going to meet your protein needs.

2) Aim for 150 minutes of moderate intensity exercise per week.

    • At least half of that exercise should be resistance exercise (lifting weights, for example).
    • If you have physical limitations, consult your doctor and a physical therapist or personal trainer to design resistance exercises you can do.
    • Aim for a variety of resistance exercises. You will only strengthen the muscles you exercise.

3) Aim for an adequate vitamin D status.

    • Start with a multivitamin containing at least 800 IU of vitamin D3.
    • Because there is large variation in the efficiency with which we convert vitamin D to 25-hydroxy vitamin D, you should get your serum 25-hydroxyvitamin D tested on a yearly basis. Your health professional can tell you if you need to take larger amounts of vitamin D3.
    • This study suggests that a serum 25-hydroxy vitamin D level of 55-69 nmol/L is optimal, and higher levels provide no additional benefit. That means there is no need to take mega-doses of vitamin D3 unless directed by your health professional.

The Bottom Line

A recent study looked at the effect of vitamin D status on muscle strength and performance in a healthy population with an average age of 69.

When they looked at handgrip strength:

  • Only 22% of the participants with an adequate vitamin D status had low handgrip strength.
  • 40% of participants who were vitamin D deficient had low handgrip strength. That’s almost a 2-fold difference.
  • Handgrip strength increased linearly with vitamin D status.

When they looked at muscle performance:

  • Only 8% of the participants with an adequate vitamin D status scored low on this test.
  • 25% of participants who were vitamin D deficient scored low on this test. That’s a 3-fold difference.
  • Muscle performance also increased linearly with vitamin D status.

The authors concluded: “Vitamin D deficiency was associated with impaired muscle strength and performance in a large study of community-dwelling older people. It is generally accepted that vitamin D deficiency should be reversed to prevent bone disease. This strategy may also protect skeletal muscle function in aging.”

If we look at the research more broadly, there are three factors that are essential for maintaining muscle mass as we age: exercise, protein, and vitamin D. Therefore, my recommendations are to:

1)  Aim for 25-30 grams of high-quality protein in each meal.

2) Aim for 150 minutes of moderate intensity exercise per week. At least half of that exercise should be resistance exercise.

3) Aim for an adequate vitamin D status (>50 nmol/L of serum 25-hydroxy vitamin D). A good place to start is with a multivitamin providing at least 800 IU of vitamin D3.

For more details on my recommendations and a discussion of why studies on vitamin D supplementation are often confusing, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

The Effect Of Vitamin D On Childhood Development

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Is Vitamin D Important During Pregnancy?

vitamin dIf you are parents, you want the best for your child. It can be nerve wracking when your child doesn’t meet the expected developmental milestones. When I saw a recent study titled “Association of maternal vitamin D status in pregnancy and neurodevelopmental outcomes in children” ( AL Darling et al, British Journal of Nutrition, 117: 1682-1692, 2017), I knew you would want to hear about it.

But first a bit of background: Based on blood 25-hydroxy vitamin D levels (considered the most accurate marker of vitamin D status):

  • 8-11% of pregnant women in the US are deficient in vitamin D (<30 nmol/L).
  • ~25% of pregnant women have inadequate vitamin D status (30-49 nmol/L).
  • ~65% of pregnant women have adequate vitamin D status (50-125 nmol/L).
  • ~ 1% of pregnant women have high vitamin D levels (>125 nmol/L).

In short, that means around 1/3 of pregnant women in the US have inadequate or deficient levels of vitamin D. The affect of inadequate vitamin D during pregnancy is not just an academic question.

It is a concern because inadequate vitamin D levels during pregnancy has been associated with gestational diabetes (diabetes during pregnancy), low birthweight babies, and a condition called pre-eclampsia (pre-eclampsia is characterized by the development of high blood pressure during pregnancy and can lead to serious, even fatal, complications for mother and baby).

The Cochrane Collaboration (considered the gold standard for evidence-based medicine) has recently reviewed the literature and has reported) that vitamin D during pregnancy “probably reduces the risk of pre-eclampsia, gestational diabetes, and the risk of having a low birthweight baby compared to placebo or no intervention.”

In short, this means the evidence is pretty good that inadequate vitamin D increases the risk of significant complications during pregnancy and that supplementation with vitamin D reduces the risk of those complications.

However, what about the effect of inadequate vitamin D during pregnancy on the development of the newborn child? Here the evidence is less clear. This study was designed to answer that question.

How Was The Study Designed?

clinical studyThis study followed neurodevelopmental milestones of 7065 children born to mothers in the Avon region of southwest England between April 1, 1991 and December 31, 1992. Maternal 25-hydroxy vitamin D levels were measured during pregnancy. The distribution of 25-hydroxy vitamin D levels in this population was very similar to that observed for pregnant mothers in the United States.

The children were followed from 6 months to 9 years of age and the following neurodevelopmental milestones were measured:

  • Gross-motor skills, fine-motor skills, social development, and communication skills were measured at 6, 18, 30, and 42 months.
  • Behavioral development (socialization, hyperactivity, emotional development, and conduct) was measured at 7 years.
  • IQ was measured at 8 years.
  • Reading skill (words/minute, accuracy, and comprehension) was measured at 9 years.

What Is The Effect Of Vitamin D On Childhood Development?

Child raising handThe study compared children of women who had inadequate vitamin D status (<50 nmol/L) during pregnancy to children of women who had adequate vitamin D status (≥50 nmol/L) during pregnancy. Here is what the study found:

The children of mothers with inadequate vitamin D during pregnancy had:

  • Delayed gross-motor skills at 18 and 30 months.
  • Delayed fine-motor skills at 30 and 42 months.
  • Delayed social development at 42 months.

However, when they looked at later years, there was no significant effect of maternal vitamin D status on:

  • Behavioral development at 7 years.
  • IQ at 8 years.
  • Reading skills at 9 years.

This is encouraging because it suggests that the effect of inadequate vitamin D during pregnancy does not have a permanent effect on childhood development. By the time they are 7 or older their nutrition and intellectual stimulation during childhood appears to outweigh the effect of their mother’s nutrition on their development.

In interpreting this information, we need to keep in mind that this study was performed in England, not in a third world country. In particular:

  • England, like the United States, has supplemental food programs for disadvantaged children.
  • England has an excellent educational system. So, we can assume these children also received intellectual stimulation as soon as they reached school age.

Is Vitamin D Important During Pregnancy?

pregnant women taking vitaminIf we focus on a healthy pregnancy, there is good evidence that inadequate vitamin D during pregnancy increases the risk of serious complications and that supplementation with vitamin D can reduce these complications. We also know that vitamin D deficiency during pregnancy can affect bone development in the newborn.

Thus, adequate vitamin D is clearly needed for a healthy pregnancy.

However, if we just consider the effect of maternal vitamin D on childhood development, it would be tempting to downplay the importance of vitamin D during pregnancy. This study focused on vitamin D, but studies focusing on other nutritional deficiencies usually give similar results.

In most of these studies, the effects of inadequate nutrition during pregnancy on childhood developmental milestones appear to be transient. Developmental delays are seen during the first few years of life but disappear as the children get older.

This is incredibly good news. It means that mild nutritional deficiencies during pregnancy do not have to handicap a child for life. If the children are given adequate nutrition and intellectual stimulation as they grow, the poor start they received in life can be erased.

It is also a caution. We already know that poor nutrition during childhood can affect a child’s behavior and intellectual development. If that child also received poor nutrition in the womb, their chances of normal childhood development may be doubly impacted.

In short, if adequate vitamin D during pregnancy improves early developmental milestones in children, that can be viewed as an added benefit.

The only question is how much vitamin D is needed. Fortunately, the present study cast some light on that question.

The study asked whether blood levels of 25-hydroxy vitamin D ≥75 nmol/L were more beneficial than blood levels ≥50 nmol/L. The answer was a clear no. That means an adequate vitamin D status during pregnancy is sufficient to support normal developmental milestones in children.

The current recommendation (DV) of vitamin D3 for pregnant women is 15 mcg (600 IU). Thus, my recommendations are:

  • If you are pregnant, be sure that your prenatal supplement provides at least 600 IU of vitamin D3.
  • If you are a woman of childbearing age, be sure that your multivitamin provides at least 600 IU of vitamin D3.
  • Slightly more is OK but avoid mega doses unless prescribed by a health professional who is monitoring your 25-hydroxy vitamin D status.
  • Because we all utilize vitamin D with different efficiencies, I would recommend asking for a 25-hydroxy vitamin D test and working with your health professional to keep your levels in the adequate range.

The Bottom Line

A recent study looked at the effect of mild vitamin D deficiency during pregnancy on childhood developmental milestones. The study found that children born to vitamin D-deficient mothers had:

  • Delayed gross-motor skills at 18 and 30 months.
  • Delayed fine-motor skills at 30 and 42 months.
  • Delayed social development at 42 months.

This is concerning. However, when they looked at later years, there was no significant effect of maternal vitamin D status on:

  • Behavioral development at 7 years.
  • IQ at 8 years.
  • Reading skills at 9 years.

The is encouraging. The reasons for this are discussed in the article above.

If we summarize this and previous studies, the bottom line is:

  • Adequate vitamin D is clearly needed for a healthy pregnancy.
  • If adequate vitamin D during pregnancy improves early developmental milestones in children, that can be viewed as an added benefit.

For more details and my recommendations on how much vitamin D you need, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Does Vitamin D Supplementation Reduce Cancer Deaths?

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Why Are Vitamin D Studies So Confusing?

Author: Dr. Stephen Chaney

 

Does vitamin D supplementation reduce cancer deaths?

vitamin d supplementationWhen I was in graduate school (which was just a few decades ago), vitamin D was thought to be important for healthy bones and teeth, and that was about it. Its role in calcium metabolism was well established, but we knew little else about its role(s) in the body. In fact, we were taught we knew all we needed to know about vitamin D.

Shortly after I graduated, it was discovered that almost every cell in our body had vitamin D receptors, and vitamin D research exploded. A few years ago, vitamin D appeared to be almost magic. Studies suggested that it:

  • Strengthened the immune system.
  • Prevented autoimmune diseases like type 1 diabetes and multiple sclerosis.
  • Reduced the risk of cancer and heart disease.
  • Helped regulate insulin levels and aided in type 2 diabetes management.
  • Supported the health of our lungs, brain, and nervous system.

Those were the headlines that you saw in the news and still see in Dr. Strangelove’s health blogs.

However, when these early studies were followed by a series of double-blind, placebo controlled clinical trials, the only benefit that was consistently validated was the strengthening of our immune system.

That has led to a series of headlines and posts in medical blogs saying things like: “Vitamin D supplements are worthless” and “You should stop taking your vitamin D supplements.”

“What is a person to believe? Why is it so confusing?”

In this week’s issue of “Health Tips From the Professor” I discuss a recent study confirming that vitamin D reduces cancer deaths. But before I do that, I will cover what I call “Vitamin D Metabolism 101” to put this week’s topic into context. Later in the article, I will discuss why vitamin D studies are so confusing.

Vitamin D Metabolism 101

 

There are two things you need to know about vitamin D metabolism to understand today’s article:

  • vitamin d supplementation 101Vitamin D occurs in two forms, D3 and D2. Vitamin D3 is the form of vitamin D that our body makes when sunlight hits our skin. Vitamin D2 is a structurally similar analog derived from yeast. For years we thought that vitamin D3 and D2 were equivalent. Vitamin D2 was less expensive, so it was one most often used in supplements.
  • Vitamin D is inactive. It needs to be activated by the body. It is first converted to 25-hydroxyvitamin D, which is the most abundant form of vitamin D in the bloodstream. It is then taken up by our cells and converted to 1,25-dihydroxyvitamin D, which is the active form. There are two things you need to know about this.
    • Since 25-hydroxyvitamin D is found in the blood, it is used as a marker to determine the vitamin D status in the body.
    • Recent studies suggest that vitamin D3 is more readily activated than vitamin D2, so it has become the preferred choice for supplementation. The result of this recent conversion from D2 to D3 means that older studies on vitamin D supplementation were primarily done with D2 while newer studies were primarily done with D3.

 

How Was The Study Done?

scientific studyThis study (Y Zhang et al, BMJ, 366:I4673, 2019  ) was a meta-analysis of 52 clinical trials with 75,454 participants looking at the relationship between vitamin D supplementation cancer deaths, heart disease deaths, and deaths due to any cause.

All the clinical trials were intervention studies in which vitamin D supplementation was compared to either a placebo or no treatment. All participants were adults over the age of 18 and without any pre-existing health conditions. The meta-analysis excluded studies if:

  • Any participants had pre-existing health conditions.
  • Any participants were pregnant or lactating women.
  • Calcium was included along with vitamin D unless both the treatment and placebo groups were given the same amount of calcium.

 

Does Vitamin D Supplementation Reduce Cancer Deaths?

The results of the study were:

  • vitamin d supplementation reduce cancer deathsVitamin D supplementation reduced cancer deaths by 16%. This difference was statistically significant. And:
    • This effect was only seen with vitamin D3 supplementation, not with vitamin D2 supplementation.
    • The reduction in cancer deaths by vitamin D was only seen in clinical trials that lasted more than 3 years but was not seen in shorter clinical trials.
  • Vitamin D supplementation did not reduce heart disease deaths. However:
    • Weaknesses in the clinical trials included in this meta-analysis made it virtually impossible to determine whether vitamin D supplementation influenced heart disease deaths or not.
  • Vitamin D supplementation did not significantly reduce death from all causes. However:
    • Death from all causes was significantly less in studies using vitamin D3 than in studies in studies using vitamin D2.
    • Death from all causes was significantly lower in clinical trials with a longer duration.

 

Why Are Vitamin D Studies So Confusing?

strengths weaknesses[Note: This section is a bit technical, so if you aren’t really interested in why vitamin D studies are confusing, you can just skip this section.]

To understand why vitamin D studies are so confusing, it is important to look at vitamin D research from a historical perspective.

Vitamin D research, like most nutrition research, starts with association studies. Association studies have suggested that vitamin D deficiency significantly increases the risk of heart disease and cancer and slightly increased the risk of death from any cause. However, association studies have their strengths and weaknesses. For example:

Strengths:

  • Association studies can follow large groups of people for a long time.
  • Association studies are particularly good at identifying the long-term effects of nutritional patterns (such as vitamin D deficiency) on health outcomes.

Weaknesses:

  • Association studies cannot prove cause and effect, so they are usually followed by intervention studies, such as the ones included in this meta-analysis.

However, intervention studies and this meta-analysis also have their own strengths and weaknesses.

Strengths: The strengths of this meta-analysis are the sample size (52 clinical trials, 75,454 participants) and the rigorous criteria for inclusion of studies in the meta-analysis.

Weaknesses: There are three kinds of weaknesses associated with this study.

  • Weaknesses of Meta-Analysis Studies: A meta-analysis increases statistical power by combining multiple studies. However, these studies do have weaknesses. For example:
    • The strength of the meta-analysis is only as good as the strength of the individual studies that go into it. This is the “garbage in – garbage out” phenomenon.
    • The individual studies use different amounts of vitamin D for different lengths of time. So, this meta-analysis is unable to tell you how much supplemental vitamin D would be required to lower your cancer risk.
  • Weaknesses of Intervention Studies: Double-blind, placebo-controlled intervention studies are considered the “gold standard” for evidence-based medicine. However, they also have their own weaknesses.
    • thumbs down symbolThey are usually small. This limits their statistical power to see small effects.
    • They are usually short.
      • This is a problem for studies looking at disease outcomes because most major diseases like heart disease or cancer develop over decades. Intervention studies like the ones included in this meta-analysis are simply too short to determine whether vitamin D supplementation could prevent those diseases.
      • It is also a problem for heart disease deaths because they often occur a decade or more after diagnosis. Thus, it is not surprising that the intervention studies included in this meta-analysis have failed to confirm an association between vitamin D and heart disease deaths.
      • However, most cancer deaths occur within the first 2-5 years after diagnosis. So, it is not surprising that intervention studies lasting 3 years or more have been able to confirm an association between vitamin D and cancer deaths.
  • Weaknesses of Studies With Popular Supplements: Once the benefits of certain nutrients show up in the headlines, people start taking those supplements. This has become a big problem for studies with vitamin D and omega-3 fatty acids. For example:
    • > 75% of Americans take a multivitamin with vitamin D, and an additional 18% of adults over 50 also take a vitamin D supplement.
    • In this meta-analysis more than half of the participants had a baseline 25-hydroxyvitamin D level of > 50 nmol/L, which the NIH considers to be adequate, prior to supplementation.
  • That means most of these studies were not asking whether correcting a vitamin D deficiency reduced the risk of death. They were asking whether giving a vitamin D supplement to someone whose vitamin D status was already adequate had any additional benefit. In this context:
    • Previous association studies have suggested that a 25-hydroxyvitamin D level of 50 nmol/L is enough to reduce heart disease deaths. Since most of the participants in the clinical trials included in this study started with this level prior to supplementation, it is not surprising that this study found no benefit of vitamin D supplementation on heart disease deaths.
    • However, previous association studies have suggested that a 25-hydroxyvitamin D level of 75 nmol/L or greater is required to reduce cancer deaths. Thus, it is not surprising that this and other studies have been able to show that vitamin D supplementation reduces cancer deaths.

In short, these weaknesses in intervention studies have made it virtually impossible to determine whether vitamin D supplementation influences heart disease deaths. Unfortunately, a meta-analysis like this one is only as good as the intervention studies that go into it. This is the “garbage in – garbage out” phenomenon.

However, those weaknesses did not apply to cancer deaths. This and other studies make a strong case that vitamin D supplementation does reduce cancer deaths.

 

What Does This Study Mean For You?

what does vitamin d supplementation mean for youAssociation studies have suggested that vitamin D deficiency significantly increases the risk of heart disease and cancer and slightly increased the risk of death from any cause.

  • This study confirms vitamin D supplementation significantly decreases cancer deaths as predicted from association studies. This observation is strengthened by two other major clinical studies in recent months that have come to the same conclusion. I reported on one of them in a recent issue of “Health Tips From The Professor.”
  • This study does not indicate an optimal dosage, but the recent VITAL study) reported that 2,000 IU of vitamin D/day was effective at reducing the risk of cancer deaths.
  • The authors of this study concluded that vitamin D supplementation has no effect on heart disease deaths. However:
  • It would be more accurate to say that weaknesses in the design of the intervention trials included in their study made it virtually impossible to determine whether vitamin D supplementation influenced heart disease deaths.
  • To adequately assess whether vitamin D reduced heart disease deaths one would need to start with a population that was deficient in vitamin D and supplement with vitamin D for 5 years or more. That kind of study has not been performed.
  • The data on whether vitamin D reduces the risk of dying from any cause is less clear.
  • This study reported that vitamin D supplementation decreased the risk of death from any cause by a non-significant 2%.
  • Two other recent meta-analyses reported that vitamin D supplementation did have a significant effect on the risk of dying from any cause. However, the risk reduction was 3% in one study and 4% in the other study.
  • Clearly, vitamin D supplementation is not going to help you live to 100.

 

The Bottom Line

 

Previous association studies have suggested that vitamin D deficiency significantly increases the risk of heart disease and cancer and slightly increased the risk of death from any cause.

A recent meta-analysis of 52 clinical trials with 75,454 participants tested those predictions by looking at the effect of vitamin D supplementation on cancer deaths, heart disease deaths, and deaths due to any cause. All the clinical trials were intervention studies in which vitamin D supplementation was compared to either a placebo or no treatment. All participants were adults over the age of 18 and without any pre-existing health conditions.

The results of this meta-analysis were:

  • Vitamin D supplementation reduced cancer deaths by 16%. This difference was statistically significant. And:
  • This effect was only seen with vitamin D3 supplementation, not with vitamin D2 supplementation.
  • The effect of vitamin D supplementation on cancer deaths is strengthened by two other major clinical studies in recent months that have come to the same conclusion.
  • This study did not indicate an optimal dosage, but the recent VITAL study reported that 2,000 IU of vitamin D/day was effective at reducing the risk of cancer deaths.
  • Vitamin D supplementation did not reduce heart disease deaths. However:
  • Weaknesses in the clinical trials included in this meta-analysis made it virtually impossible to determine whether vitamin D supplementation influenced heart disease deaths or not.
  • Vitamin D supplementation did not significantly reduce death from all causes. However:
  • Death from all causes was significantly less in studies using vitamin D3 than in studies using vitamin D2.
  • Death from all causes was significantly lower in clinical trials with a longer duration.

For more details on the study and what it means for you, read the article above. Also, if you would like to understand why there is so much confusion about vitamin D’s health benefits, it is also discussed in the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

The Truth About Vitamin D

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Does Vitamin D Reduce Risk Of Heart Disease & Cancer?

Author: Dr. Stephen Chaney

 

the truth about vitamin dYou have every right to be confused. One day you are told that vitamin D reduces your risk of heart disease and cancer. The next day you are told vitamin D makes has no effect on those diseases. You are told vitamin D is a waste of money. What should you believe?  What is the truth about vitamin D?

In mid-November a major clinical study called VITAL was published. It examined the effect of vitamin D and omega-3s on heart disease and cancer risk. Last week I wrote about the omega-3 portion of the study. This week I will cover the vitamin D portion of the study.

Once again, if you rely on the media for your information on supplementation, you are probably confused. Headlines ranged from “Vitamin D Is Ineffective For Preventing Cancer And Heart Disease to “Vitamin D Lowers Odds Of Cancer Death.” What is the truth?

The problem is that reporters aren’t scientists. They don’t know how to interpret clinical studies. What they report is filtered through their personal biases. That is why I take the time to carefully evaluate the clinical studies, so I can provide you with accurate information. Let me sort through the dueling headlines and give you the truth about vitamin D, cancer, and heart disease.

How Was The Study Designed?

the truth about vitamin d studyThe VITAL study (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403) enrolled 25,871 healthy adults (average age = 67) in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had preexisting cancer or heart disease. The characteristics of the study group were typical of the American population at that age, namely:

  • The average BMI was 28, which means that most of the participants were significantly overweight.
  • 7% of them had diabetes.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 65% of the participants to determine 25-hydroxyvitamin D levels (a measure of vitamin D status) at baseline and at the end of the first year. The participants were given either 2,000 IU of vitamin D/day or a placebo and followed for an average of 5.3 years.

There were two important characteristics of the participants in this study that may have influenced the outcome.

  • The average 25-hydroxyvitamin D level of participants at the beginning of the study was 31 ng/ml (78 nmol/L). The NIH considers 20-50 ng/ml (50-125 nmol/L) to be the optimal level of 25-hydroxyvitamin D for most physiological functions. This means that study participants started in the middle of the optimal range with respect to vitamin D status.

[Note: The NIH defines the 20-50 ng/ml range as “adequate.”  However, I know many of my readers like to aim beyond adequate to reach what they consider to be “optimal.”  In the case of vitamin D, that might not be a good idea. The NIH considers anything above 50 ng/ml as associated “with potentially adverse effects.”  For that reason, I will refer to the 20-50 ng/ml range as optimal for this article. I wouldn’t want to encourage my readers to be aiming for above 50 ng/ml.]

  • Only 12.7% of participants had 25-hydroxyvitamin D levels below 20 ng/ml, which the NIH considers to be inadequate. The results with this group were not statistically different from the study participants with optimal vitamin D status, but it is not clear that there were enough people in this subgroup for a statistically valid comparison with participants starting with an optimal vitamin D status.
  • At the end of the first year, 25-hydroxyvitamin D levels in the treatment group increased to 42 ng/ml (105 nmol/L), which is near the upper end of the optimal range. Thus, for most of the participants, the study was evaluating whether there was a benefit of increasing vitamin D status from the middle to the upper end of the optimal range.
  • The study allowed subjects to continue taking supplements that contained up to 800 IU of vitamin D. While the authors tried to correct for this statistically, it is a confounding variable.

Does Vitamin D Reduce The Risk Of Cancer?

 

the truth about vitamin d and cancerYou may remember from last week that omega-3s were more effective for reducing heart disease risk than for reducing cancer risk. What is the truth about vitamin D and cancer risk?   The results are reversed for vitamin D, so I will discuss cancer first.

The study reported that vitamin D supplementation did not reduce a diagnosis of invasive cancer of any type, breast cancer, prostate cancer, or colon cancer during the 5.3-year time-period of this study. This was the result that was reported in the abstract and was what lazy journalists, who never read past the abstract, reported.

However, the rest of the study was more positive. For example, occurrence of invasive cancer of any type was reduced by:

  • 23% in African-Americans.
  • 24% in patients with a healthy body weight.

Several previous studies have suggested that vitamin D may be more effective at preventing cancer in people with a healthy body weight, but the mechanism of this effect is currently unknown.

Most previous studies have not included enough African-Americans to determine whether they respond more favorably to vitamin D supplementation. However, African-Americans have a higher risk of cancer, so this finding deserves follow-up.

In addition, when the study looked at deaths from cancer, the results were very positive. For example:

  • Cancer deaths during the 5.3-year study period were reduced by 17%.
  • The longer vitamin D supplementation was continued the more effective it became at reducing cancer deaths. For example,
  • When the authors excluded cancer deaths occurring during the first year of supplementation, vitamin D reduced cancer deaths by 21%.
  • When the authors excluded cancer deaths occurring during the first two years of supplementation, vitamin D reduced cancer deaths by 25%.

Finally, no side effects were noted in the vitamin D group.

 

Does Vitamin D Reduce The Risk Of Heart Disease?

 

the truth about vitamin d and heart diseaseThe VITAL study also looked at the effect of vitamin D on heart disease risk. What is the truth about vitamin D and heart disease?  The results from this study were uniformly negative. There was no effect of vitamin D supplementation on all major cardiovascular events combined, heart attack, stroke, or death from heart disease. Does that mean vitamin D has no role in reducing heart disease risk? That’s not clear.

The authors had a thought-provoking explanation for why the results were negative for heart disease, but positive for cancer. Remember that the participants in this trial started with a 25-hydroxyvitamin D level of 31 ng/ml and increased it to at least 42 ng/ml with vitamin D supplementation.

The authors stated that previous studies have suggested the 25-hydroxyvitamin D level associated with the lowest risk for heart disease is between 20 and 25 ng/ml. If that is true, most of the participants in this trial were already in the lowest possible risk for heart disease with respect to vitamin D status before the study even started. There would be no reason to expect additional vitamin D to further reduce their risk of heart disease.

In contrast, the authors said that previous studies suggest the 25-hydroxyvitamin D level associated with the lowest risk of cancer deaths is above 30 ng/ml. If that is true, it would explain why vitamin D supplementation in this study was effective at reducing cancer deaths.

However, previous placebo-controlled clinical studies have also been inconclusive with respect to vitamin D and heart disease. My recommendation would be to think of adequate vitamin D status as part of a holistic approach to reducing heart disease – one that includes a heart-healthy diet and a heart-healthy lifestyle – rather than a “magic bullet” that decreases heart disease risk by itself.

As for heart-healthy diets, I discuss the pros and cons of various diets in my book, “Slaying The Food Myths.”  As I discuss in my book, the weight of scientific evidence supports primarily plant-based diets that include omega-3s as heart healthy. As an example, the Mediterranean diet is primarily plant-based and is rich in healthy oils like olive oil and omega-3s. It is associated with reduced risk of both heart disease and cancer.

 

What Is The Truth About Vitamin D?

 

the truth about vitamin d signThere is a lot of confusion around the question of whether vitamin D reduces the risk of cancer. This study strengthened previous observation suggesting that vitamin D supplementation decreases cancer deaths. However, it is also consistent with previous studies that have failed to find an effect of vitamin D on cancer development. How can we understand this apparent discrepancy? The authors provided a logical explanation. They pointed out that:

  • Cancer development takes 20-30 years while this clinical study lasted only 5.3 years. That means that vitamin D supplementation only occurred at the tail end of the cancer development process. In fact, the cancer was already there in most of the patients in the study who developed cancer. It just had not been diagnosed yet. In the words of the authors: “Given the long latency for cancer development, extended follow-up is necessary to fully ascertain potential effects [of vitamin D supplementation].”
  • In contrast, none of the patients had been diagnosed with cancer when they entered the trial. That means that the patients were diagnosed with cancer during the 5.3-year study period. They were receiving extra vitamin D during the entire period of cancer treatment. Thus, the effect of vitamin D on reducing cancer deaths was easier to detect.

What Does This Study Mean For You?

the truth about vitamin d questionsVitamin D Is Likely To Decrease Your Risk Of Dying From Cancer: When you combine the results of this study with what we already know about vitamin D and cancer, the results are clear. Vitamin D appears to reduce your risk of dying from cancer. More importantly, the longer you have been supplementing with vitamin D, the greater your risk reduction is likely to be.

Vitamin D May Decrease Your Risk Of Developing Cancer: Association studies suggest that optimal vitamin D status is associated with decreased cancer risk, especially colon cancer risk. However, the long time for cancer development means that we may never be able to prove this effect through double-blind, placebo-controlled clinical trials.

Holistic Is Best: When you combine the VITAL study results with what we already know about vitamin D and heart disease, it appears that supplementing with vitamin D is unlikely to reduce your risk of developing heart disease unless you are vitamin D deficient. However, a holistic approach that starts with a healthy, primarily plant-based diet and makes sure your vitamin D status is adequate is likely to be effective.

The same is likely true for cancer. While the latest study suggests that vitamin D supplementation reduces your risk of dying from cancer, those vitamin D supplements are likely to be even more effective if you also adopt a healthy diet and lifestyle.

How Much Vitamin D Do You Need? The optimal dose of vitamin D is likely to be different for each of us. One of the things we have learned in recent years is that there are significant differences in the efficiency with which we convert vitamin D from diet and/or sun exposure into the active form of vitamin D in our cells. Fortunately, the blood test for 25-hydroxyvitamin D is readily available and is widely considered to be an excellent measure of our vitamin D status.

I recommend that you have your blood level of 25-hydroxyvitamin D tested on an annual basis. Based on the best currently available data, I recommend you aim for >20 ng/ml (50 nmol/L) if you wish to minimize your risk of heart disease and >30 ng/ml (75 nmol/L) if you wish to minimize your risk of cancer. If you can achieve those levels through diet and a multivitamin supplement, that is great. If not, I would recommend adding a vitamin D supplement until those levels are achieved.

Finally, you shouldn’t think of vitamin D as a magic bullet. If you are a couch potato and eat sodas and junk food, don’t expect vitamin D to protect you from cancer and heart disease. You should think of maintaining adequate 25-hydroxyvitamin D levels as just one component of a holistic approach to healthy, disease-free living.

 

The Bottom Line

 

There is a lot of confusion around the question of whether vitamin D reduces the risk of cancer and heart disease. A major clinical study has just been published that sheds light on these important questions. It reported:

  • Vitamin D did not decrease the risk of developing cancer during the 5.3-year study duration. The authors pointed out that cancer takes 20-30 years to develop, which means their study was probably too short to detect an effect of vitamin D on the risk of developing cancer.
  • Vitamin D did decrease the risk of dying from cancer, and the longer people were supplementing with vitamin D the bigger the protective effect of vitamin D was.
  • Vitamin D did not decrease the risk of heart disease. However, most study participants had a level of 25-hydroxyvitamin D that was optimal for reducing the risk of heart disease at the beginning of the study. There was no reason to expect that extra vitamin D would provide additional benefit.
  • With respect to both cancer and heart disease the best advice is to:
    • Get your 25-hydroxyvitamin D levels tested on an annual basis and supplement, if necessary, to keep your 25-hydroxyvitamin D levels in what the NIH considers to be an adequate range (20-50 ng/ml).
    • We do not have good dose response data for the beneficial effects of vitamin D on heart disease and cancer. However, according to this article, previous studies suggest you may want to am for 25-hydroxyvitamin D levels above 20 ng/ml to reduce the risk of heart disease and above 30 ng/ml to reduce your risk of cancer.
    • Consider vitamin D as just one component of a holistic approach to healthy, disease-free living.

For more details about the interpretation of these studies and what they mean for you, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

Does Vitamin D Reduce Cholesterol In Children?

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Is Vitamin D Associated With Heart Disease Risk?

Author: Dr. Stephen Chaney

 

vitamin-d-reduce-cholesterol-childrenNot too many years ago, we thought of vitamin D as affecting bone density and little else. Then we discovered that almost every cell in our body has vitamin D receptors. This has lead to research suggesting that vitamin D affects our health in many ways that were unimaginable only a couple of decades ago.

For example, low vitamin D levels are associated with increased risk of heart disease. The linkage between vitamin D and heart disease has not been proven. Nor do we know the mechanism. However, this has lead to ongoing research asking if there is any relationship between vitamin D and cholesterol metabolism.

The answer appears to be yes. Several studies have suggested a correlation between low vitamin D levels and elevated total cholesterol, LDL cholesterol, and triglycerides – all risk factors for heart disease.

The next question is how early in life is this correlation found. Again, some studies have suggested that the same correlation between low vitamin D and high levels of unhealthy lipids are found in teens. But, what about pre-teens, children who haven’t gone through puberty yet? That’s what this study was designed to determine.

 

How Was The Study Done?

vitamin-d-reduce-cholesterol-children studyThe current study  was based on data collected from 419 children, ages 6-8, in the Physical Activity and Nutrition in Children (PANIC) Study in Eastern Finland. This was a lifestyle study that collected information on body weight, diet, and activity levels.

Fasting blood samples were also collected and analyzed for blood lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) and for 25-hydroxyvitamin D (25(OH)D), which is considered the most accurate measure of vitamin D status. The National Institutes of Health considers:

  • <30 nmol/L of 25(OH)D an indicator of vitamin D deficiency.
  • 30 to <50 nmol/L 25(OH)D an indicator of vitamin D insufficiency.
  • ≥50 nmol/L 25(OH)D an indicator of adequate vitamin D status.

To put this study in perspective, vitamin D status is a major concern in Finland because of its proximity to the Arctic Circle. There is little sunlight in the winter, and, although the days are long in the summer, the sun is weak. The major sources of vitamin D in the Finnish diet are fish, vitamin D-fortified fluid milk products, vitamin D-fortified fat spreads, and vitamin D supplementation. Vitamin D fortification was introduced in Finland in 2003. Vitamin D supplementation has also become increasing popular. The number of people using vitamin D supplements has increased from 11% in 2000 to 41% in 2011.

A recent study  looking a vitamin D status between 2000 and 2011 found that the combination of food fortification and vitamin D supplementation has been successful at improving vitamin D status in the Finnish population, increasing average 25(OH)D levels from 48 nmol/L to 65 nmol/L.

 

Does Vitamin D Reduce Cholesterol In Children?

vitamin dIn this study the mean serum 25(OH)D in the children was 68.1 nmol/L. 20% of the children had serum 25(OH)D below 50 nmol/L, and only 4 children (1%) had serum 25(OH)D below 30 nmol/L. When 25(OH)D levels were compared with blood lipid levels:

  • Higher serum 25(OH)D levels were associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
  • The association between higher 25(OH)D levels and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.

What Does This Mean For You?

I don’t want to overinterpret the study. Not all studies show an inverse association between 25(OH)D and cholesterol levels. Most of the previous studies have also indicated that higher 25(OH)D levels were associated increased HDL levels, while this study found higher 25(OH)D levels associated with decreased HDL levels. Much more research needs to be done.

However, this study is yet another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.

My recommendations are to:

  • Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
  • Get your serum 25(OH)D level determined and take vitamin D supplements if it is low.

 

The Bottom Line

 

A recent study of vitamin D status in Finnish children ages 6-8 found:

  • Higher vitamin D status was associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
  • The association between better vitamin D status and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.

This study is another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.

My recommendations are to:

  • Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
  • Get your serum 25-hydroxyvitamin D level determined and take vitamin D supplements if it is low.
  • Make sure your children are getting enough vitamin D in their diet and have optimal serum 25-hydroxyvitamin D.

For more details, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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