Does Maternal Vitamin D Affect Childhood ADHD?

Can ADHD Be Prevented?

vitamin dIf you are pregnant, or of childbearing age, should you be supplementing with vitamin D? Increasingly, the answer appears to be yes.

1) 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 insufficient vitamin D status (30-49 nmol/L).

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

2) The Cochrane Collaboration (considered the gold standard for evidence-based medicine) has recently concluded that supplementation with vitamin D reduces the risk of significant complications during pregnancy.

3) Another recent study found that inadequate vitamin D status during pregnancy delayed several neurodevelopmental milestones in early childhood, including gross motor skills, fine motor skills, and social development.

If neurodevelopmental milestones are affected, what about ADHD? Here the evidence is not as clear. Some studies have concluded that vitamin D deficiency during pregnancy increases the risk of ADHD in the offspring. Other studies have concluded there is no effect of vitamin D deficiency on ADHD.

Why the discrepancy between studies?

  • Most of the previous studies have been small. Simply put, there were too few children in the study to make statistically reliable conclusions.
  • Most of the studies measured maternal 25-hydroxyvitamin D levels in the third trimester or in chord blood at birth. However, it is during early pregnancy that critical steps in the development of the nervous system take place.

Thus, there is a critical need for larger studies that measure maternal vitamin D status in the first trimester of pregnancy. This study (M Sucksdorff et al, Journal of the American Academy of Child & Adolescent Psychiatry, 2020, in press) was designed to fill that need.

How Was The Study Done?

Clinical StudyThis study compared 1,067 Finnish children born between 1998 and 1999 who were subsequently diagnosed with ADHD and 1,067 matched controls without ADHD. There were several reasons for choosing this experimental group.

  • Finland is among the northernmost European countries, so sun exposure during the winter is significantly less than for the United States and most other European countries. This time period also preceded the universal supplementation with vitamin D for pregnant women that was instituted in 2004.

Consequently, maternal 25-hydroxyvitamin D levels were significantly lower than in most other countries. This means that a significant percentage of pregnant women were deficient in vitamin D, something not seen in most other studies. For example:

    • 49% of pregnant women in Finland were deficient in vitamin D (25-hydoxyvitamin D <30 nmol/L) compared to 8-11% in the United States.
    • 33% of pregnant women in Finland had insufficient vitamin D status (25-hydroxyvitamin D 30-49.9 nmol/L) compared to 25% in the United States.
  • Finland, like many European countries, keeps detailed health records on its citizens. For example:
    • The Finnish Prenatal Study collected data, including maternal 25-hydroxyvitamin D levels during the first trimester), for all live births between 1991 and 2005.
    • The Care Register for Health Care recorded, among other things, all diagnoses of ADHD through 2011.

Thus, this study was ideally positioned to compare maternal 25-hydroxyvitamin D levels during the first trimester of pregnancy with a subsequent diagnosis of ADHD in the offspring. The long-term follow-up was important to this study because the average age of ADHD diagnosis was 7 years (range = 2-14 years).

Does Maternal Vitamin D Affect Childhood ADHD?

Child With ADHDThe answer to this question appears to be a clear, yes.

If you divide maternal vitamin D levels into quintiles:

  • Offspring of mothers in the lowest vitamin D quintile (25-hydroxyvitamin D of 7.5-21.9 nmol/L) were 53% more likely to develop ADHD than offspring of mothers in the highest vitamin D quintile (49.5-132.5 nmol/L).

When you divide maternal vitamin D levels by the standard designations of deficient (<30 nmol/L), insufficient (30-49.9 nmol/L), and sufficient (≥50 nmol/L):

  • Offspring of mothers who were deficient in vitamin D were 34% more likely to develop ADHD than children of mothers with sufficient vitamin D status.

The authors concluded: “This is the first population-based study to demonstrate an association between low maternal vitamin D during the first trimester of pregnancy and an elevated risk for ADHD diagnosis in offspring. If these findings are replicated, they may have public health implications for vitamin D supplementation and perhaps changing lifestyle behaviors during pregnancy to ensure optimal maternal vitamin D levels.”

Can ADHD Be Prevented?

Child Raising HandI realize that this is an emotionally charged title. If you have a child with ADHD, the last thing I want is for you to feel guilty about something you may not have done. So, let me start by acknowledging that there are genetic and environmental risk factors for ADHD that you cannot control. That means you could have done everything right during pregnancy and still have a child who develops ADHD.

Having said that, let’s examine things that can be done to reduce the risk of giving birth to a child who will develop ADHD, starting with vitamin D. There are two aspects of this study that are important to keep in mind.

#1: The increased risk of giving birth to a child who develops ADHD was only seen for women who were vitamin D deficient. While vitamin D deficiency is only found in 8-11% of pregnant mothers in the United States, that is an average number. It is more useful to ask who is most likely to be vitamin D deficient in this country. For example:

  • Fatty fish and vitamin D-fortified dairy products are the most important food sources of vitamin D. Fatty fish are not everyone’s favorite and may be too expensive for those on a tight budget. Many people are lactose intolerant or avoid milk for other reasons. If you are not eating these foods, you may not be getting enough vitamin D from your diet. This is particularly true for vegans.
  • If you have darker colored skin, you may have trouble making enough vitamin D from sunlight. If you are also lactose intolerant, you are in double trouble with respect to vitamin D sufficiency.
  • Obesity affects the distribution of vitamin D in the body. So, if you are overweight, you may have low 25-hydroxyvitamin D levels in your blood.
  • The vitamin D RDA for pregnant and lactating women is 600 IU, but many multivitamin and prenatal supplements only provide 400 IU. If you are pregnant or of childbearing age, it is a good idea to look for a multivitamin or prenatal supplement that provides at least 600 IU, especially if you are in one of the high risk groups listed above.
  • Some experts recommend 2,000 to 4,000 IU of supplemental vitamin D. I would not recommend exceeding that amount without discussing it with your health care provider first.
  • Finally, for reasons we do not understand, some people have a difficult time converting vitamin D to the active 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in their bodies. If you are pregnant or of childbearing age, it is a good idea to have your blood 25-hydroxyvitamin D levels determined and discuss with your health care provider how much vitamin D you should be taking. Many people need more than 600 IU to reach vitamin D sufficiency status.

#2: Maternal vitamin D deficiency has a relatively small effect (34%) on the risk of the offspring developing ADHD. That means assuring adequate vitamin D status during pregnancy should be part of a holistic approach for reducing ADHD risk. Other factors to consider are:

  • Low maternal folate and omega-3 status.
  • Smoking, drug, and alcohol use.
  • Obesity.
  • Sodas and highly processed foods.

Alone, each of these factors has a small and uncertain influence on the risk of your child developing ADHD. Together, they may play a significant role in determining your child’s risk of developing ADHD.

In closing, there are three take-home lessons I want to leave you with:

1) The first is that there is no “magic bullet”. There is no single action you can take during pregnancy that will dramatically reduce your risk of giving birth to a child who will develop ADHD. Improving your vitamin D, folate, and omega-3 status; avoiding cigarettes, drugs, and alcohol; achieving a healthy weight; and eating a healthy diet are all part of a holistic approach for reducing the risk of your child developing ADHD.

2) The second is that we should not think of these actions solely in terms of reducing ADHD risk. Each of these actions will lead to a healthier pregnancy and a healthier child in many other ways.

3) Finally, if you have a child with ADHD and would like to reduce the symptoms without drugs, I recommend this article.

The Bottom Line

A recent study looked at the correlation between maternal vitamin D status during the first trimester of pregnancy and the risk of ADHD in the offspring. The study found:

  • Offspring of mothers who were deficient in vitamin D were 34% more likely to develop ADHD than children of mothers with sufficient vitamin D status.

The authors concluded: “This is the first population-based study to demonstrate an association between low maternal vitamin D during the first trimester of pregnancy and an elevated risk for ADHD diagnosis in offspring. If these findings are replicated, they may have public health implications for vitamin D supplementation and perhaps changing lifestyle behaviors during pregnancy to ensure optimal maternal vitamin D levels.”

In the article above I discuss what this study means for you and other factors that increase the risk of giving birth to a child who will develop ADHD.

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.

 

Are Pregnant Women and Children Dangerously Deficient in Omega-3s?

What Is The Omega-3 Status Of The American Population?

Author: Dr. Stephen Chaney

 

pregnant women omega 3 deficient fishIt is no secret that the American population is deficient in omega-3s. Numerous studies have documented that fact. There are many reasons for Americans’ low intake of omega-3s:

  • The high price of omega-3-rich fish.
  • Concerns about sustainability, heavy metal contamination, and/or PCB contamination of omega-3 rich fish.
  • Misleading headlines claiming that omega-3 supplements are worthless and may even do you harm.

Of course, the questions you are asking are probably?

  • How deficient are we?
  • Does it matter?

The latest study (M Thompson et al, Nutrients, 2019, 11: 177, doi: 10.3390/nu11010177) goes a long way towards answering those important questions.

How Was The Study Done?

scientific studyThis study used data on 45,347 Americans who participated in NHANES surveys between 2003 and 2014. (NHANES or National Health and Nutrition Examination Surveys is a program run by the CDC that is designed to assess the health and nutritional status of adults and children living in the United States).

EPA and DHA intake from foods was based on the average of two 24-hour dietary recall interviews. Trained dietary interviewers collected detailed information on all foods and beverages consumed during the past 24 hours.

To assess EPA and DHA intake from supplements study participants were asked what supplements they had taken in the past 30 days, how many days out of 30 they had taken it, and the amount that was taken on those days.

 

What Is The Omega-3 Status Of The American Population?

 

omega 3 statusThe results of the NHANES surveys were shocking.

In terms of total EPA+DHA intake:

  • EPA+DHA intake across all age groups was lower than recommended.
  • Toddlers (ages 1-5), children (ages 6-11), and adolescents (ages 12-19) had lower EPA+DHA intakes than adults (ages 20-55) and seniors (ages > 55).
  • Women had lower EPA+DHA intakes than men.
  • Pregnant women and women of childbearing age did not differ in their EPA+DHA.
  • Pregnant women consumed less fish than women of childbearing age (perhaps because of concerns about heavy metal contamination).
  • Pregnant women consumed more omega-3 supplements.

In terms of EPA+DHA from supplements:

  • Less than 1% of the American population reported using omega-3 supplements.
  • The one exception was pregnant women. 7.3% of pregnant women reported taking an omega-3 supplement.
  • People taking omega-3 supplements had significantly higher EPA+DHA intake than people not taking omega-3 supplements.
  • This was also true for pregnant women. Those taking omega-3 supplements had higher EPA+DHA intake.

Of course, like any clinical study, it has strengths and weaknesses.

The biggest weakness of this study is that omega-3 intake is based on the participants recall of what they ate. The strengths of the study are its size (45,347 participants) and the fact that its estimate of omega-3 intake is consistent with several smaller studies.

 

Are Americans Deficient In Omega-3s?

 

pregnant women omega 3 deficient questionsNow we are ready to answer the questions I posed at the beginning of this article. Let’s start with the first one: “How deficient are we?”

You would think the answer to that question would be easy. It is not. This study provides a precise estimate of American’s omega-3 intake. The problem is there is no consensus as to how much omega-3s we need. There is no RDA for omega-3s.

There are, in fact, three sets of guidelines for how much omega-3s we need, and they disagree.

  • The World Health Organization (WHO) recommendations for EPA+DHA intake range from 100-150 mg/day at ages 2-4 years to 200-500 mg/day for adults.
  • The US National Institute of Medicine (IOM) recommendations for EPA+DHA intake range from 70 mg/day for ages 1-3 to 110 mg/day for adult females and 160 mg/day for adult males.
  • As if that weren’t confusing enough, an international group of experts recently convened for a “Workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids” (Workshop). This group recommended an EPA+DHA intake of 440 mg/day for adults and 520 mg/day for pregnant and lactating women.

Using these recommendations as guidelines, this study reported that:

  • EPA+DHA intake for children 1-5 years old was ~25% of the WHO recommendations and ~40% of IOM recommendations.
  • EPA+DHA intake for children 6-11 years old was ~27% of WHO recommendations and ~40% of IOM recommendations.
  • EPA+DHA intake for adolescents 12-19 years old was ~50% of IOM recommendations (The WHO did not have a separate category for adolescents.
  • EPA+DHA intake for adults 20-55 years old was ~30% of WHO recommendations, and ~65% of IOM recommendations.
  • EPA+DHA intake for seniors >55 years old was 38% of WHO recommendations and 82% of IOM recommendations.
  • EPA+DHA intake for pregnant women was ~20% of Workshop recommendations (The WHO and IOM did not have a separate category for pregnant women).

While the percentage deficiency varied according to the EPA+DHA guidelines used, it is clear from these results that Americans of all age groups are not getting enough omega-3s from their diet.

The authors concluded: “We found omega-3 intakes across all age groups was lower than recommended amounts.”

 

Are Pregnant Women and Young Children Dangerously Deficient In Omega-3s?

 

danger symbolWhile the authors concluded that all age groups were deficient in omega-3s, they were particularly concerned about the omega-3 deficiencies in pregnant women and young children.

The authors said: “Taken together, these findings demonstrate that low omega-3 fatty acid intake is consistent among the US population and could increase the risk for adverse health outcomes, particularly in vulnerable populations (e.g., young children and pregnant women).”

In part, the focus on young children and pregnant women was based on their very low omega-3 intake. With intakes at 20-27% of recommended levels, I would consider these groups to be dangerously deficient in omega-3s.

pregnant women omega 3 deficient pregnancyHowever, the focus on young children and pregnant women was also based on the seriousness of the adverse health outcomes associated with low omega-3 intake in these population groups. This answers the second question I posed at the beginning of this article: “Does it matter?”

According to the authors low intake of EPA and DHA during pregnancy and early childhood is associated with maternal depression, pre-term births, low birth-weight babies, increased risk of allergies and asthma, problems with learning and cognition, and other neurocognitive outcomes.

None of these associations between low omega-3 intake and adverse health outcomes have been proven beyond a shadow of a doubt, but the evidence is strong enough that we should be alarmed by the very low omega-3 intake in pregnant women and young children.

There is, however, a simple solution. The authors of this study concluded: “Individuals taking EPA/DHA containing supplements had significantly elevated intake compared to individuals not taking omega-3 fatty acid-containing supplements or not reporting any supplement use.”

omega 3 supplementsThey went on to say: “As supplement use is associated with increased omega-3 intake, supplementation could be an important source of EPA/DHA, particularly for pregnant women given their lower fish consumption compared to non-pregnant women of childbearing age.”

I agree. Given the low omega-3 intake in these population group and current guidelines for omega-3 intake. I recommend:

  • Pregnant & lactating women (and women of childbearing age who might become pregnant) take an omega-3 supplement providing around 520 mg of EPA+DHA/day.
  • Young children (ages 1-5) take an omega-3 supplement providing around 100 mg of DHA/day.

Of course, this study also confirmed that Americans of all age groups are not getting enough omega-3s from their diet, and low omega-3 intake may increase the risk of heart disease. Furthermore, recent studies have shown that high purity omega-3 supplements may reduce heart disease risk.

You will find my recommendations for omega-3 supplementation for adults in a previous issue of “Health Tips From the Professor.”

 

The Bottom Line

 

The largest study to date (45,347 participants) measured omega-3 intake for Americans of all ages and compared that to current recommendations for omega-3 intake.

The authors of the study concluded:

  • “We found omega-3 intakes across all age groups was lower than recommended amounts.”
  • “Low omega-3 fatty acid intake … could increase the risk for adverse health outcomes, particularly in vulnerable populations (e.g., young children and pregnant women.”

In part, the focus on young children and pregnant women was based on their very low omega-3 intake. With intakes at 20-27% of recommended levels, I would consider these groups to be dangerously deficient in omega-3s.

However, the focus on young children and pregnant women was also based on the seriousness of the adverse health outcomes associated with low omega-3 intake in these population groups.

  • According to the authors low intake of EPA and DHA during pregnancy and early childhood is associated with maternal depression, pre-term births, low birth-weight babies, increased risk of allergies and asthma, problems with learning and cognition, and other neurocognitive outcomes.

There is, however, a simple solution. The authors of this study also concluded:

  • “Individuals taking EPA/DHA containing supplements had significantly elevated intake compared to individuals not taking omega-3 fatty acid-containing supplements or not reporting any supplement use.”
  • “As supplement use is associated with increased omega-3 intake, supplementation could be an important source of EPA/DHA, particularly for pregnant women given their lower fish consumption compared to non-pregnant women of childbearing age.”

For more details on the study and my recommendations for omega-3 supplementation, 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.

Health Tips From The Professor