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Prenatal Supplements Strike Out Again

May 9, 2023 by Dr. Steve Chaney

Is It Three Strikes And You Are Out?

Author: Dr. Stephen Chaney

If you are pregnant, you want the best for your unborn baby. Your doctor has recommended a prenatal supplement, but do the prenatal supplements on the market meet your needs? A few months ago, I shared two studies that concluded that most prenatal supplements on the market are woefully inadequate.

In fact, the authors said, “[Our] analysis found that prenatal supplements vary widely in content, often only contain a subset of essential vitamins, and the levels were often below…recommendations.”

In other words, their study found that most prenatal vitamins on the market may not be adequate to support your needs and the needs of your child through pregnancy and breastfeeding.

Now, a third study on the topic has been published (KA Saunders et al, American Journal of Clinical Nutrition, 117: 823-829, 2023. It differs from the previous studies in that:

1) The previous two studies took a comprehensive approach, while this study focused on 6 key nutrients.

The previous studies included all nutrients important for a healthy pregnancy including choline, iodine, and vitamin K, which have only recently been shown to be important for a healthy pregnancy.

This study focused on 6 nutrients, vitamin A, vitamin D, folic acid, calcium, iron, and omega-3 fatty acids, which have long been recognized as essential for a healthy pregnancy.

2) The previous two studies focused on prenatal supplements, while this study focused on all supplements that might be taken by pregnant women.

3) The previous two studies asked whether supplements provided recommended amounts of all nutrients needed for a healthy pregnancy. This study took a “Goldilocks approach” and asked whether levels of these 6 essential nutrients were appropriate (“just right”). The study:

Started by determining the intake of these 6 key nutrients by American women. The authors of the study then added the amount of each nutrient provided by the supplements in their study to the amount of that nutrient in the diet of American women and:

- Calculated the minimum amount of each nutrient that would be needed to assure that 90% of American women taking a particular supplement would meet the recommended intake for pregnant and lactating women.

- Calculated the maximum amount of each nutrient provided by supplements in their study to assure that that 90% of American women taking that supplement would not get potentially toxic amounts of that nutrient.

In other words, for each of the 6 nutrients they calculated a supplemental dose range that was neither too low nor too high. They called this the “appropriate dose range” for each nutrient. Goldilocks would have called it “just right”.

I’m sure you are anxiously waiting to learn what their study found. But before we go there, I will describe how the study was done.

How Was The Study Done?

For the dietary intake portion of the study, the authors used dietary intake data previously collected from the Environmental Influences on Child Health Outcomes (ECHO) study.

The ECHO study is a consortium of 69 medical centers across multiple states. It is an observational study of mothers and their offspring designed to understand the effects of early life exposures on child health and development.

The current study analyzed dietary intake data for 2450 participants from 6 medical centers across 5 states in the ECHO study. The women in this study were diverse with respect to ethnicity, education, and weight.

All pregnant women in the current study completed at least one 24-hour dietary recall between 6-week gestation until delivery (24% completed one dietary recall. 76% completed two or more dietary recalls). Dietary intake was generally assessed with an expert interviewer and included all foods and beverages consumed in the previous 24 hours.

For the supplement portion of the study, the authors used the NIH Dietary Supplement Label Database because it is the most complete listing of supplements in the US. The authors selected 20,547 supplements that contained at least one of the 6 essential nutrients from this database.

To determine which of the 20,547 supplements contained appropriate levels of the 6 nutrients (vitamin A, vitamin D, folic acid, calcium, iron, and omega-3 fatty acids) selected for this study, the authors used the process described in the introduction above. Briefly:

The authors added the amount of each nutrient provided by the supplements in their study to the amount of that nutrient in the diet of American women and:

Calculated the minimum amount of each nutrient that would be needed to assure that 90% of American women taking a particular supplement would meet the recommended intake for pregnant and lactating women.

Calculated the maximum amount of each nutrient provided by supplements in their study to assure that that 90% of American women taking that supplement would not get potentially toxic amounts of that nutrient.

In other words, for each of the 6 nutrients they calculated a supplemental dose range that was neither too low nor too high. They called this the “appropriate dose range” for each nutrient.

Why Are The 6 Nutrients Included In This Study Important?

Dietary Intake Is Often Inadequate

The diet analysis of pregnant American women in this study found:

42% were at risk of inadequate vitamin A intake.

96% were at risk of inadequate vitamin D intake.

45% were at risk of inadequate folic acid intake.

55% were at risk of inadequate calcium intake.

93% were at risk of inadequate iron intake.

67% were at risk of inadequate omega-3 intake.

The percentage of women at risk for inadequate intake of these nutrients varied with age, ethnicity, and income levels. But the overall message is clear. Most American women are not getting enough of these essential nutrients from their diet alone.

The Risk of Inadequate and Excessive Intake Of These Nutrients

These 6 nutrients were chosen in part because reviews by the Cochrane Collaboration have concluded that inadequate intake of these nutrients are associated with complications during pregnancy and delivery. They can also adversely affect the health and normal development of the baby.

This is important because the Cochrane Collaboration is considered the Gold Standard of clinical studies. You can find a more detailed description of Cochrane Collaboration studies and why they are the Gold standard here.

[Note: The Cochrane Collaboration has not yet evaluated choline, iodine, and vitamin K for pregnant women, but their inclusion in prenatal supplements is supported by multiple clinical studies.]

In addition, excess intake of all these nutrients except omega-3s can harm both the fetus and the mother. The is why the Food and Nutrition Board has set ULs (Upper Limits – the level above which toxicity can occur) for 5 of the 6 nutrients. This is important because previous studies have suggested that up to 25% of women may be getting toxic levels of one or more of these nutrients when you consider both their dietary intake and their prenatal supplement.

Summary

In other words, both too little and too much of these nutrients can harm the mom and her baby. It is critical that prenatal supplements get the dosing right.

It is for that reason that the authors of this study have set an “appropriate dose range” (high enough that 90% of women have enough of each nutrient to prevent deficiency and low enough that 90% of women do not exceed the UL for each nutrient) as the standard for evaluating the adequacy and safety of supplements for pregnant women.

Prenatal Supplements Strike Out Again

Of the 20,547 supplements (421 labeled as prenatal supplements) available on the US market as of December 31, 2022, the investigators reported that:

Only 69 (0.3%) supplements contained all 6 nutrients considered essential for a healthy pregnancy.

Only 1 supplement contained all 6 nutrients at the appropriate doses, and it wasn’t even labeled as a prenatal supplement.

In addition:

One supplement containing all 6 nutrients put 100% of the women in their study at risk for excessive intake of folic acid.

Another supplement containing all 6 nutrients put 46% of the women in their study at risk of inadequate calcium intake.

The authors concluded, “Almost no US dietary supplements provide key nutrients in the doses needed for pregnant women. Affordable and convenient products that fill the gap between food-based intake and estimated requirements of pregnancy without inducing excess intake are needed to support pregnant women and their offspring.”

In short, the conclusion of this study can be summed up as, “Prenatal Supplements Strike Out Again”.

[Note: It sometime takes a while for supplement labels to be posted in the NIH Dietary Supplement Label Database. The authors acknowledged that this study may not include supplements introduced or reformulated in the last quarter of 2022.]

Is It Three Strikes And You Are Out?

If you are pregnant or thinking of becoming pregnant, this should be a wake-up call.

70% of pregnant women in this country take prenatal supplements, usually based on recommendations by their health care provider. They assume the prenatal supplements meet their needs and the needs of their unborn baby.

Yet three studies evaluating the adequacy of prenatal supplements have been published in the past few months. They took very different approaches in evaluating the supplements. But all three studies concluded that the vast majority of prenatal supplements on the market are woefully inadequate.

You may be wondering, “Is it three strikes, and you are out?” Are there no decent prenatal supplements on the market? The answer to those questions is, “No. There are good prenatal supplements on the market.”

You may be wondering how I can say that in the face of such overwhelming negative data. That’s because while all 3 studies were very good studies, they each had “blind spots”:

1) Each of the studies used very stringent criteria for identifying adequate prenatal supplements. In some cases, their criteria were stricter than the RDA recommendations and the recommendations of the American College of Obstetrics and Gynecology for pregnant and lactating women. It could be argued that their criteria were too stringent.

2) In the case of the current study, it could also be argued that evaluating only 6 nutrients is not a good criterion for evaluating the adequacy of prenatal supplements. For example, I looked up the one supplement rated as adequate in this study. It does provide appropriate doses of the 6 nutrients this study focused on. It also provides appropriate doses of vitamin K and iodine. But it does not provide choline. It is a very good supplement for women, but it is not the perfect prenatal supplement.

So, what can you do? How can you find the best prenatal supplement for you? Unfortunately, you cannot rely on advice from your friends or your health professional. You cannot rely on advertisements. That is a good place to start, but you have to do your own sleuthing.

With that in mind, I have listed 7 simple rules for selecting the best possible prenatal supplement in my article about the first two studies. Use these rules for evaluating every prenatal supplement you come across. Happy sleuthing.

The Bottom Line

A recent study evaluated all 20,547 supplements on the US market to see if they met the needs of pregnant women in this country.

They focused on 6 nutrients (vitamin A, vitamin D, folic acid, calcium, iron, and omega-3s) known to be essential for a healthy pregnancy.

They determined the dietary intake for all 6 nutrients in a cross section of pregnant women in the US.

They added the amount of the 6 nutrients in each of the 20,547 supplements to the dietary intake of those nutrients by pregnant women.

They then asked which supplements provided the “appropriate dose” of all 6 nutrients. They defined “appropriate dose” as the dose range that was.

- High enough to prevent deficiency of that nutrient in 90% of pregnant women taking the supplement…and…

- Low enough to prevent toxicity from that nutrient in 90% of pregnant women taking the supplement.

In other words, for each of the 6 nutrients they calculated a supplemental dose range that was neither too low nor too high.

Of the 20,547 supplements (421 labeled as prenatal supplements) available on the US market:

Only 69 (0.3%) supplements contained all 6 nutrients they considered essential for a healthy pregnancy.

Only 1 supplement contained all 6 nutrients at the appropriate doses, and it wasn’t even labeled as a prenatal supplement.

If you are pregnant or thinking of becoming pregnant, this should be a wake-up call.

Yet three studies evaluating the adequacy of prenatal supplements have been published in the past few months. And all three studies concluded that the vast majority of prenatal supplements on the market are woefully inadequate.

You may be wondering how I can say that in the face of such overwhelming negative data. That’s because while all 3 studies were very good studies, they each had “blind spots”:

For more details on this study and 7 tips on finding the best prenatal supplement 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.

____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Do Supplements Interfere With Chemotherapy?

February 2, 2021 by Dr. Steve Chaney

Should You Avoid Supplement Use During Chemotherapy?

Since much of my research career was devoted to cancer research, specifically developing new chemotherapeutic drugs for treating cancer, many of you have asked me the question: “Do food supplements interfere with chemotherapy?”

My answer has always been that it is theoretically possible, but that we don’t really know the answer because the necessary studies have not been done.

However, I do know that most cancer drugs are retained in the body for a short period of time. So, my pragmatic advice has always been to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. That is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

That is why I was interested when I saw the recent headlines claiming certain supplements may interfere with chemotherapy for breast cancer. I wanted to find out if someone had finally done a definitive study on the effect of supplementation on chemotherapy.

So, I have reviewed the study (CB Ambrosone et al, Journal of Clinical Oncology, 38, 804-815, 2020) behind the headlines and will share what I discovered.

How Was The Study Done?

This study was an offshoot of a much larger Phase III clinical trial designed to determine the best schedule for administering three drugs (doxorubicin, cyclophosphamide, and paclitaxel) to patients with high-risk early-stage breast cancer.

The 1,134 patients enrolled in this study were given questionnaires on their use of supplements when they registered for the study to determine supplement use prior to the study. They were also given questionnaires when they completed chemotherapy to determine supplement use during chemotherapy.

The questionnaires documented use of:

Multivitamins

The antioxidants vitamin C, vitamin A, vitamin E, carotenoids, and coenzyme Q10.

Vitamin D.

The B vitamins vitamin B6, vitamin B12, and folic acid.

The minerals iron and calcium.

Omega-3 fatty acids.

Glucosamine, melatonin, and acidophilus.

Recurrence of the breast cancer and death from breast cancer were measured 6 months after chemotherapy ended.

Do Supplements Interfere With Chemotherapy?

The study reported:

The number of patients using individual antioxidant supplements was too low to determine whether individual antioxidants had any effect on treatment outcomes.

When the patients using any antioxidant supplement were pooled into a single group, there was a nonsignificant association between antioxidant supplement use during chemotherapy and an increased risk of breast cancer recurrence and death from breast cancer.

Iron use during chemotherapy was significant associated with an increased risk of breast cancer recurrence.

Vitamin B12 use during chemotherapy was significantly associated with increased risk of breast cancer recurrence and death from breast cancer.

Multivitamin use was not associated with either recurrence or death from breast cancer.

The number of patients using the other supplements was too low to determine whether those supplements had any effect on treatment outcomes.

The authors concluded: “Associations between survival outcomes and use of antioxidant and other dietary supplements are consistent with recommendations for caution among patients when considering the use of supplements, other than a multivitamin, during chemotherapy.”

This is the conclusion that generated the headlines you may have seen.

However, in their discussion the authors conceded that a previous review concluded that, “…insufficient evidence existed with regard to the safety of dietary supplements [during chemotherapy] to make recommendations, and that still may be the case.”

I will discuss the reasons for their disclaimer below. However, I will point out that disclaimers like this never seem to make it into the headlines you read.

What Are The Strengths And Weaknesses Of This Study?

The only strength of this study is that it was performed in the context of an ongoing clinical trial, with surveys conducted before chemotherapy and during chemotherapy to assess supplement use.

However, the study had multiple weaknesses that limit the ability to draw any firm conclusions from the study.

#1: The number of people using supplements in this study was very small. For example:

Only 200 people took any antioxidants during chemotherapy.

Only 137 people took a vitamin B12 supplement during chemotherapy.

Only 109 people took an iron supplement during chemotherapy.

To put this into perspective, if a drug company were submitting a new drug for approval to the FDA, they would be required to submit data from ~50-100-fold more cancer patients to prove that the drug was effective.

With this small number of supplement users, even “statistically significant” observations are questionable.

In contrast, the number of people taking a multivitamin during chemotherapy was 497. Thus, those data were a little stronger than the data for individual supplements.

#2: They did not ask why people were taking supplements. It turns out that the patients who used supplements were older and sicker. They were more likely to be overweight and to have type 2 diabetes.

These are patients who are also more likely to have poor outcomes from chemotherapy. The authors tried to correct for that, but it is virtually impossible to make these corrections when the number of patients taking supplements is so low.

#3: They did not ask about the dose of supplements people were taking.

Multivitamins typically contain RDA levels of antioxidants and vitamin B12, so it would be safe to assume that RDA levels of antioxidants and vitamin B12 are safe during chemotherapy.

Approximately 50% of the women in the study were premenopausal, so it is likely that they were taking a multivitamin with iron. That suggests that RDA levels of iron are safe during chemotherapy for premenopausal women.

In short, the association between supplement use and poorer outcomes from chemotherapy is tenuous. If there is any association, it is likely with high dose individual supplements rather the lower levels of the same nutrients found in a multivitamin.

Is An Effect Of Supplement Use On Chemotherapy Plausible?

As a biochemist, the next question I ask is whether there is a plausible mechanism for an effect of any of these supplements on chemotherapy outcomes.

For two of the drugs in the regimen (paclitaxel and cyclophosphamide), free radical formation may contribute to their effectiveness, but it is not their main mechanism of action. Thus, it is plausible that high dose antioxidant supplements could make these drugs less effective, but the effect should be relatively small.

Tumors require high amounts of iron for proliferation, so it is plausible that excess iron could make tumors more resistant to chemotherapy. However, for premenopausal women, multivitamins with iron did not interfere with the drugs used in this study. Thus, it appears likely that RDA levels of iron, where appropriate, do not interfere with chemotherapy.

The authors said that the reason for the observed effects of vitamin B12 on chemotherapy in their study “remains to be understood”. However, the answer might be found in the dosage of vitamin B12. A previous study reported that doses of vitamin B12 that were greater than 20 times the RDA increased the risk of lung cancer.

If people in this study were taking doses of vitamin B12 in excess of 20 times the RDA, it would provide a plausible explanation for B12 interfering with chemotherapy. If not, there is no known explanation. In any case, I do not recommend taking such high doses of any supplement.

Should You Avoid Supplement Use During Chemotherapy?

Now, let’s get back to the original question: “Should you avoid supplement use during chemotherapy?” If you read the headlines saying, “Supplement Use During Chemotherapy May Be Risky”, you might think that the answer is an unqualified yes. That is also what your doctor is likely to think.

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.

A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and chemotherapy. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.

Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

The Bottom Line

Recent headlines have warned, “Supplement Use During Chemotherapy May Be Risky”. Is that true?

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.

A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and the chemotherapy drugs you are on. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.

Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

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.

Use of Sports Supplements By Young Athletes

October 31, 2013 by Dr. Steve Chaney

Are Sports Supplements Effective? Are They Safe?

Author: Dr. Pierre DuBois

In recent years, the use of sports supplements by young athletes has increased dramatically. The most commonly used sports supplements among teenagers of all ages were vitamins and minerals, though “ergogenic aids” are used by some teen athletes specifically to enhance performance. Among these performance-enhancing supplements are substances such as caffeine, creatine, ephedra and other stimulants, human growth hormone (HGH) and anabolic steroids.

Of the vitamin and mineral supplements, mutivitamins, vitamin C, calcium and iron were reported as being taken most often. While the risks of taking vitamin supplements is relatively low, there is some concern that young athletes may then progress to taking more dangerous substances under the impression that they are as harmless as vitamins and minerals. And while the risk of overdose with vitamins and minerals is low, it is not nonexistent, and some vitamins can be toxic when too much is taken (such as iron and vitamin A) or may interact with other vitamins or drugs.

Although many performance-enhancing supplements are advertised as being safe – especially those made from natural compounds – a great number of them have not been tested by any regulatory agency, so their actual safety is not known. In addition, there are no formal guidelines for dosage in many cases, so there could be adverse side effects if too much is inadvertently taken.

The pressure to excel at sports is greater than ever, and there is increasing competition to get into elite sports programs where they have a better chance of being discovered by professional sports scouts looking for the next big star. The possibility of fame and fortune can be a strong enticement to young athletes to try performance-enhancing supplements to give them an edge over their competition. And often it is their coach that suggests or encourages this practice.

According to studies done on high school athletes, they report taking supplements to not only enhance performance, but also to encourage growth and muscle development, prevent illness and reduce fatigue. Supplement use was greatest among athletes who practiced two or more different sports and those who were required to “bulk up”, such as wrestlers and weight lifters.

While the opinions of friends, teammates and coaches were a big influence on the decision of young football players to take supplements (particularly creatine), it was their parents who had the greatest amount of influence on their decision. So it is incredibly important for parents to be educated as to the benefits and drawbacks of each of these supplements for young athletes.

The Bottom Line:

There is tremendous pressure on teenage athletes to qualify for elite programs that will increase their chances of being selected for the top college teams and eventually getting onto professional teams. Because of that, the use of sports supplements by teenage athletes is commonplace.

Vitamin and mineral supplements are generally harmless unless taken in excessive amounts.

Performance-enhancing sports supplements, on the other hand, are poorly regulated. Many are useless and others are potentially harmful. In next week’s “Health Tips From The Professor”, I’ll give you some examples of sports supplements you might want to avoid.

If you are the parent of a teen athlete, have a conversation with your child about supplements. Don’t lecture, but involve them in the process of doing research. You may be surprised what you both find.

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.