Which Nutrients Prevent Prenatal Depression?

What Does This Study Mean For You?

Author: Dr. Stephen Chaney 

Yes, you read the headline correctly. Everyone talks about postnatal depression. But prenatal depression is also a “thing”, especially during the third trimester.

  • Worldwide, 4-20% of women experience some degree of depression during the third trimester – with pregnant women in high-income countries at the lower end (4-10%) of depression risk.
  • In contrast, the incidence of postnatal depression is 10-15%.

It is probably no coincidence that the incidence of depression is greatest during the third trimester and during the postnatal period.

  • The third trimester is the most difficult part of pregnancy for many women.
  • When a woman brings her baby home from the hospital her orderly life becomes chaotic.

But what role does nutrition play?

  • While not definitive, many studies suggest that supplementation with B vitamins, especially folic acid, B6, and B12; omega-3 fatty acids; vitamin D; and iron reduce the risk of postnatal depression.
  • However, there is much less information on which nutrients reduce the risk of prenatal depression.

Based on studies suggesting both iron and vitamin D deficiencies may negatively impact mental health, the authors of this study (JL Evanchuk et al, The Journal Of Nutrition. 154, 174-184, 2024) set out to determine whether iron and/or vitamin D deficiencies increase the risk of prenatal depression during the first trimester.

How Was This Study Done?

Clinical StudyThe authors recruited 2189 newly pregnant mothers from Calgary and Edmonton in Ontario Canada between 2009 and 2012. Participants in the study visited clinics in the area upon entry into the study; midway through the first, second, and third trimesters; and at multiple timepoints up to 3 months during the postpartum period.

In addition to the usual pregnancy wellness tests, participants filled out a 24-hour dietary recall and a Supplemental Intake Questionnaire to determine intakes of iron and vitamin D.

Note: The participants were all advised to take some form of prenatal supplement during the study. That’s because prenatal supplements are considered “the standard of care” for pregnant woman, so it would be considered unethical not to include a prenatal supplement in this study.

At the mid-point of the second trimester blood samples were drawn and analyzed for biomarkers of iron and vitamin D insufficiency. For iron the biomarkers were serum ferritin, soluble transferrin receptor, and hepcidin. For vitamin D, the biomarkers were 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and 3-epi-25-hydroxyvitamin D.

Iron deficiency was defined as serum ferritin levels <15 µg/L. Vitamin D insufficiency was defined as 25-hydroxyvitamin D levels < 75nmol/L. The other biomarkers were used to confirm these diagnoses.

Maternal depression was measured midway through the third trimester and ~3 months postpartum using 10-item questionnaire called the Edinburg Postnatal Depression Scale (EPDS). The EPDS ranks depression on a scale of 0 to 30, with a score of ≥13 considered an indication of likely depression.

The characteristics of the women enrolled in this study were:

  • Average age = 31.5
  • Average prepregnancy BMI = 23 (healthy weight).
  • Married or cohabitating with a partner = 97%.
  • Highly educated (college or postgraduate degree) = 68%.
  • Income above $70,000/year = 78%.
  • First child = 54%.
  • White = 80%.

Based on the Edinburg Depression Scale, probably depression for the 1822 women who completed the study was 5.6% during the third trimester and 4.4% 3 months postpartum.

Note: The low incidence of depression seen in this study was probably due to:

  • The women in this study were of high socioeconomic status and were receiving excellent healthcare.
  • The women in this study were taking prenatal supplements that provided both iron and vitamin D.

Which Nutrients Prevent Prenatal Depression? 

pregnant women taking vitaminsAs I mentioned when describing how the study was designed, all participants in this study were advised to take a prenatal supplement. Consequently:

  • 94% of the women in this study were taking a supplement containing iron with an average supplemental iron intake of 26 mg/day.
    • Note: The RDA for iron during pregnancy is 30 mg/day and most prenatal supplements provide 27 mg/day.
  • 68% of the women in this study were taking a supplement containing vitamin D, with an average supplemental vitamin D intake of 330 IU/day.
    • Note: The RDA for vitamin D during pregnancy is 600 IU/day, but most prenatal supplements provide far less than that.

When the investigators looked at iron and vitamin D status during the second trimester:

  • 63.3% of the women had adequate levels of both iron and vitamin D.
  • 14.8% of the women were low in vitamin D but had adequate iron levels.
  • 18.4% of the women were low in iron but had adequate levels of vitamin D.
  • 3.5% of the women were low in both iron and vitamin D.

RDAs are supposed to be enough to meet the nutrient requirements of 97-98% of healthy individuals, so it is perhaps surprising to see so many women with insufficient levels of iron (21.9%) and/or vitamin D (18.3%) in this study. This could be due to:

  • Insufficient intake.
    • This is a likely explanation for vitamin D because the supplements women were using in this study provided around half the recommended RDA for vitamin D and the women lived at a northern latitude where sun exposure makes a small contribution to vitamin D levels.
    • However, this is a less likely explanation for insufficient iron levels because the supplements provided 87% of the RDA for iron.
  • Inadequate RDAs. Studies like this one provide a rigorous test for the adequacy of existing RDAs. This study suggests the existing RDA for iron is adequate to meet the needs of ~80% of pregnant women, which is reassuring. However, it may need to be increased to reach the goal of meeting the iron requirements for 97-98% of pregnant women.

But the important question is whether the iron and vitamin D insufficiencies seen in this study mattered. The data suggested that they did.

  • For pregnant women with low iron, but adequate vitamin D levels in the second trimester, there was a small, but significant, increased risk of experiencing depression symptoms in the third trimester.
  • For pregnant women with low iron and vitamin D levels in the second trimester, the risk of experiencing depression symptoms in the third trimester increased by 2.2 points in the 30-point Edinburg Depression Scale.
    • This is equivalent to a 7.4% increased risk of depression from deficiencies of iron and vitamin D alone – and these are only 2 of at least 8 nutrients thought to be associated with maternal depression.

The authors concluded, “Maternal iron and vitamin D biomarkers, measured during midpregnancy, were independently associated with third trimester maternal depression symptoms…This investigation is one of the first to report on the combined adequacy of maternal iron and vitamin D status during pregnancy and its impact on maternal depression.

The novelty of this work reinforces the need to ask similar questions [with other nutrients and] in other pregnant populations. Future investigations should report on the status of multiple nutrients and explore their independent and combined impact on health outcomes of pregnant individuals and their children.”

What Does This Study Mean For You?

Questioning WomanDepression during pregnancy is bad for you. And because your fetus can sense your mood, it is bad for your baby. So, what should you do?

You can consult with your doctor about which antidepressants are safe to take during pregnancy. But the truth is there are no good choices. There are some antidepressants that are off limits. There are other antidepressants that appear to have little short-term risks, but we have no idea if there are long-term risks for your child.

So, what about natural approaches? Let’s start with nutrition.

The biggest takeaway from this study is that prenatal supplements may not be sufficient to prevent nutritional deficiencies that may cause prenatal depression for pregnant women.

  • This does not mean that every pregnant woman suffering prenatal depression should increase their iron and vitamin D levels.
  • However, if you are experiencing prenatal depression, you might want to ask your doctor about checking your iron and vitamin D status to determine if extra iron and/or vitamin D would be beneficial.

And to put this study into its proper perspective we need to remember that iron and vitamin D deficiencies are only two of many nutrients that may increase the risk of prenatal depression.

For example, in addition to iron and vitamin D, prenatal depression is associated with deficiencies of:

  • B vitamins, especially folate, B6 and B12. Most prenatal supplements provide the recommended RDA of folate for pregnant women, but not all contain RDA amounts of B6 and B12.
  • Calcium and magnesium. Very few prenatal supplements provide the recommended RDA for calcium and magnesium.
  • Omega-3s, especially DHA. Very few prenatal supplements provide DHA, and the few that do usually provide inadequate amounts of DHA.

So, when you are having your nutrition conversation with your doctor, you might not want to limit your conversation to iron and vitamin D.

Alternately, as I suggested last week’s issue of “Health Tips From the Professor”, you might wish to add a multivitamin supplement and an omega-3 supplement providing at least 300 mg of DHA plus EPA. This simple step would be sufficient to assure you have adequate levels of nutrients thought to be important for reducing the risk of prenatal depression.

And, of course, there are other lifestyle factors, as well. For example:

  • Diets high in highly processed foods are known to increase the risk of depression. And whole food, primarily plant-based diets decrease the risk of depression.
  • Overweight and obesity increase the risk of depression.
  • Regular exercise decreases the risk of depression.

The Bottom Line

A recent study looked at whether taking a prenatal supplement was sufficient to eliminate deficiencies of iron and vitamin D during pregnancy and whether deficiencies of these two nutrients during the second trimester of pregnancy increased the risk of depression during the third trimester.

When the investigators looked at iron and vitamin D status during the second trimester:

  • 14.8% of the women were low in vitamin D but had adequate iron levels.
  • 18.4% of the women were low in iron but had adequate levels of vitamin D.
  • 3.5% of the women were low in both iron and vitamin D.

But the important question is whether the iron and vitamin D insufficiencies seen in this study mattered. The data suggested that they did.

  • For pregnant women with low iron, but adequate vitamin D levels in the second trimester, there was a small, but significant, increased risk of experiencing depression symptoms in the third trimester.
  • For pregnant women with low iron and vitamin D levels in the second trimester, the risk of experiencing depression symptoms in the third trimester increased by 2.2 points in the 30-point Edinburg Depression Scale.
  • This is equivalent to a 7.4% increased risk of depression from deficiencies of iron and vitamin D alone.

When you consider that iron and vitamin D are just two of 8 or more nutrients thought to be important for preventing depression during pregnancy, the question becomes what you can do to decrease your risk of developing depression during pregnancy and after the birth of your child.

For more details about the study and what it means 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

___________________________________________________________________________

About The Author

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Does The Mediterranean Diet Improve Pregnancy Outcomes?

Is The Mediterranean Diet Overrated?

Author: Dr. Stephen Chaney

healthy pregnancyYou may have noticed that certain celebrities are singled out for fame and acclaim, while others of equal talent and accomplishment are virtually ignored.

The same thing occurs in the scientific realm. At present, the Mediterranean diet is the darling of the diet world. Study after study is designed to test the benefits of the Mediterranean diet while other excellent diets are ignored. I will discuss this phenomenon and ask whether the Mediterranean diet is overrated at the end of this article. But let’s start at the beginning.

Multiple studies have shown that the Mediterranean diet is associated with lower risk of heart disease, diabetes, and high blood pressure. Some studies suggest it is associated with lower risk of kidney disease and Alzheimer’s disease.

Studies also suggest that the Mediterranean diet is associated with an increase in lifespan (how long you live) and healthspan (how long you enjoy good health). In other words, these studies suggest that following a Mediterranean diet adds years to your life and life to your years.

Most of these studies have been done with men. However, there are enough studies with women to be confident that the beneficial effects of the Mediterranean diet on disease risk and lifespan apply to women as well as to men.

But what about pregnancy? Does the Mediterranean diet support a healthy pregnancy? Here the data are less clear. Three studies have been published showing that pregnant women who follow the Mediterranean diet are less likely to experience gestational diabetes (diabetes during pregnancy).

But what about other adverse pregnancy outcomes that can affect the health of both the mother and her baby such as:

  • Gestational hypertension (high blood pressure during pregnancy).
  • Preeclampsia (high blood pressure and protein in the urine that occurs late in pregnancy. It may be associated with liver and/or kidney damage).
  • Eclampsia (a severe form of preeclampsia where the mother also has seizures).
  • Preterm birth (birth prior to 37 weeks).
  • Low birth weight infant.

This study (N Makarem et al, JAMA Network Open. 5(12): e2248165, 2022) was designed to look at the effect of the Mediterranean diet on all seven of these adverse pregnancy outcomes.

How Was This Study Done?

Clinical StudyThe data for this analysis came from a large clinical trial called the Nulliparous Pregnancy (first time pregnancy) Outcomes Study. The study enrolled 7798 women in their first trimester of pregnancy from 8 medical centers across the country. The women were racially, ethnically, and geographically diverse.

Diet around the time of conception was assessed with a food frequency questionnaire administered at the mother’s first visit to the clinic (usually around 6-13 weeks after conception). The participants were asked to indicate their usual intake of 120 foods and beverages during the past 3 months. In other words, the participants were asked to indicate their diet prior to conception through early pregnancy.

Adherence to the Mediterranean diet was assessed using something called the aMed or Alternative Mediterranean Diet Score (a version of the Mediterranean diet that considers US food preferences). Each participant was assigned one point for:

  • Above average intake of vegetables, fruits, nuts, whole grains, legumes, fish, and the ratio of monounsaturated fat to saturated fat.
  • Below average intake of red meat and processed meats.

Alcohol intake was a bit more complicated:

  • Participants were given 1 point for one 12-ounce can of beer, 5 ounces of wine, or 1.5 ounces of liquor and 0 points for consumption above or below that amount.

The points for all these dietary components were added up to give an aMed score of 0-9, with 9 representing the best adherence to the Americanized version of the Mediterranean diet.

Does The Mediterranean Diet Improve Pregnancy Outcomes?

Mediterranean Diet FoodsThe authors started out by dividing the pregnant moms into thirds according to adherence to an Americanized Mediterranean diet based their aMed score. When they compared those in the top third (aMed scores of 6-9) with those in the lowest third (aMed scores of 0-3) the risk of developing:

  • Any adverse pregnancy outcome was reduced by 21%.
  • Preeclampsia or eclampsia were reduced by 28%.
  • Gestational diabetes was reduced by 37%.
  • Other adverse pregnancy outcomes were not statistically different.

Next, they asked whether stricter adherence to the Mediterranean diet would be even more beneficial. To do this New Parentsthey divided the pregnant moms into fifths. When they compared those in the top fifth (aMed scores of 7-9) with those in the lowest fifth (aMed scores of 0-2) the risk of developing:

  • Any adverse pregnancy outcome was still reduced by 20%, but…
    • Preeclampsia and eclampsia were reduced by 35%.
    • Gestational diabetes was reduced by 54%.
    • Other adverse pregnancy outcomes were not statistically different.

When they broke the results down into participant subgroups:

  • The effect of the Mediterranean diet on any adverse pregnancy outcomes was not affected by prepregnancy BMI (a measure of obesity), race, or ethnicity.
  • However, it was significantly affected by age. Any adverse pregnancy outcome was reduced by:
    • 48% in women over 35.
    • 15% in women younger than 35.

The authors concluded, “We demonstrate that a Mediterranean diet pattern is associated with lower risk of developing any APO [adverse pregnancy outcome] and multiple individual APOs in US women…Our findings add to the growing body of evidence that the Mediterranean diet pattern may play an important role in preserving the health of women across the lifespan, including during pregnancy.”

Is The Mediterranean Diet Overrated?

At the beginning of this article, I posed the question, “Is the Mediterranean diet overrated?” When the authors broke the results down by food group, it suggested the answer may be, “Yes”.

The reduction in any adverse pregnancy outcome was associated with:

  • Above average consumption of vegetables, fruits, legumes, and fish.

The reduction in preeclampsia and eclampsia was associated with:

  • Above average consumption of vegetables, fruits, and fish.

The reduction in gestational diabetes was associated with:

  • Above average consumption of vegetables, and…
  • Below average consumption of red meat and processed meats.

If you are saying to yourself, “Wait a minute. Doesn’t this pattern of food consumption describe almost any whole food, primarily plant-based diet”, you would be correct. In theory, this pattern of food consumption is also consistent with the DASH diet, Mind diet, Scandinavian diet, flexitarian diet, pesco-vegetarian diet, and semi vegetarian diet, just to name a few.

In my opinion there is nothing about this study that restricts beneficial pregnancy outcomes to the Mediterranean diet. However, I do have a few caveats about that statement.

  • A good prenatal supplement is a good idea to make sure you are getting the vitamins and minerals required for a successful pregnancy. However, as I have described in a previous article finding a good prenatal supplement may not be as easy as it should be.
  • Choline is important for a healthy pregnancy, and it is missing in many prenatal supplements. While choline is found in many plant foods, the best sources of choline are fish, poultry, eggs, and dairy. You want to be sure to include some of these in your diet and/or look for a prenatal supplement containing at least 200 mg of choline.
  • The long chain omega-3s DHA and EPA are important for a healthy pregnancy and are also missing or present in inadequate amounts in many prenatal supplements.
  • The best dietary sources of DHA and EPA are cold water fish like salmon, tuna, sardines, and herring. That means:
    • If you are following the DASH diet or something similar, you will want to substitute fish for red meat.
    • A pesco-vegetarian diet is probably a better choice for you than a semi-vegetarian because it focuses on fish as the main protein source in place of poultry and red meat.
    • If you are not a big fish lover, you should consider an omega-3 supplement supplying at least 250 mg of long chain omega-3s with most of it as DHA.

What Does This Study Mean For You?

Questioning WomanLet me close by putting a few things into perspective.

1) When I said that the Mediterranean diet may be overrated, I did not mean it wasn’t an excellent diet. I simply mean it is probably not any better than other whole food, primarily plant-based diets (with the caveats I listed above).

2) The pregnancy benefits of the Mediterranean diet (and other healthy diets) are related to the overall health of the mother. A good prenatal supplement is still important to assure adequate amounts of all the nutrients essential for a healthy pregnancy.

  • For example, the authors pointed out that most women do not change their dietary habits when they become pregnant, and that their pregnancy is more likely to be successful if they are in good health at the time of conception.

3) Most diets of women of childbearing age do not provide adequate amounts of choline and omega-3s, so it is important to choose a prenatal supplement program that provides adequate amounts of choline and omega-3s.

4) Adequate calories and protein are also important for a healthy pregnancy.

  • Pregnancy is not the time to lose weight, even if you are overweight.
  • A vegan diet may not provide enough protein unless it has been designed by a dietitian.
  • You should discuss your current diet with your health care provider, and they may refer you to a dietitian if necessary.

The Bottom Line 

The Mediterranean Diet is currently the darling of the nutrition world. Yes, numerous studies have shown that people consuming the Mediterranean diet are healthier and live longer. But we find ourselves in a situation where study after study is being designed to look for other benefits of the Mediterranean diet while equally healthy diets are being ignored.

The study discussed in this article is a perfect example. It was designed to determine whether adherence to the Mediterranean diet prior to and during pregnancy reduced the risk of experiencing adverse outcomes during pregnancy – outcomes that could affect the health of the mother and her baby.

The answer to that question was, “Yes”. Adherence to the Mediterranean diet reduced the risk of:

  • Any adverse outcome during pregnancy by 20%.
  • Preeclampsia and eclampsia by 35%.
  • Gestational diabetes by 54%.

And the risk reduction was even greater for women over 35.

However, when the investigators looked at the foods responsible for the reduction in adverse pregnancy outcomes, it appears likely that any whole food, primarily plant-based diet would provide the same results.

In short, this study showed that adherence to the Mediterranean diet improves pregnancy outcomes. The authors chose to focus on the Mediterranean diet because of its popularity. But their data show it is likely that other whole food, primarily plant-based diets would be equally beneficial.

For more information on this study and what it means 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

Prenatal Supplements Strike Out Again

Is It Three Strikes And You Are Out?

Author: Dr. Stephen Chaney

Pregnant CoupleIf 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?

clinical studyFor 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? 

pregnant women taking vitaminsIf 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.

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.”

[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 or early 2023.]

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. And 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”:

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

 

 

Is Your Prenatal Supplement Adequate?

What Should You Look For In A Prenatal Supplement?

Author: Dr. Stephen Chaney

pregnant women taking omega-3You want to do the best for your unborn child. So, you try to find the best prenatal supplement. You may ask your doctor to recommend a prenatal supplement. You may ask your best friend what supplement she used when she was pregnant. Or perhaps you scan online reviews of prenatal supplements by random dietitians or nutrition gurus to select the “best” prenatal supplements.

Then you read the supplement label or the company’s website and see claims like:

  • “Supports optimal nutrition before, during, and after pregnancy”
  • “Packed with 16 nutrients to support fetal development, immunity, energy metabolism, and more”
  • “Concise prenatal formula supports both bone and brain development”

It sounds so good. You think you have found the perfect prenatal supplement. “Right?”

Perhaps not. A recent study (JB Adams et al, Maternal Health, Neonatology, and Perinatology, 8:4, 2022) did an in-depth review of prenatal supplement recommendations and how well prenatal supplements on the market met those recommendations.

The results were not encouraging. The authors concluded, “[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 may not be adequate to support your needs and the needs of your child through pregnancy and breastfeeding.

I know this is likely to be a topic of great concern for many of you. So, I will examine the study in detail and give you some guidelines for selecting the perfect prenatal supplement.

How Was This Study Done?

clinical studyThis study can be divided into two parts.

#1: What Should The Ideal Prenatal Supplement Contain:

The authors started off by reevaluating the optimal recommendations for prenatal supplements. They reviewed over 200 articles, focusing on articles that:

  • Provided insight into optimal dosage [of essential nutrients] such as treatment studies on the effects of different doses on outcomes and biomarkers.
  • Were larger, more rigorously designed, such as randomized double-blind placebo-controlled studies.

The studies included in their review fell into three categories:

  1. The association of low levels of vitamins with health problems [during pregnancy and in the child after birth].

2) Studies on the changes in [blood] vitamin levels during pregnancy [when the mother is either] un-supplemented or supplemented (The blood level of many vitamins decreases dramatically during pregnancy without supplementation).

3) Clinical trials on the effect of vitamin supplementation on health problems [during pregnancy].

They used these data to create their recommendations for what an ideal prenatal supplement should contain. In some cases, their recommendations were higher than current RDA recommendations for pregnant women.

#2: How Do Currently Available Prenatal Supplements Compare With Their Recommendations For The Ideal Supplement?

For this part of the study, they created a comprehensive list of the nutrients provided by 188 prenatal supplements currently on the market using databases created by the National Institutes of Health. Where these databases were outdated, the nutrient list for that supplement was updated using information on the manufacturer’s websites or labels on retail websites such as Amazon.

Finally, they compared the nutrient content of all 188 prenatal supplements with their recommendations for the ideal prenatal supplement.

Is Your Prenatal Supplement Adequate?

Questioning WomanThere are four points I wish to make before I review the results of this study.

  1. I suspect you are most interested in finding out how prenatal supplements on the market compare with their recommendations for an ideal supplement, so that is what I will discuss below.

2) As I mentioned above, some of their recommendations exceed the current Daily Value (DV) recommendations for pregnant and lactating women. I will point that out whenever it significantly affects the comparisons.

3) The authors of this article made the point that most women going on a prenatal supplement will probably discontinue taking their multivitamin supplement. Thus, their recommendations included nutrients commonly included in multivitamin supplements. This is a valid point, and something you should consider when choosing a prenatal supplement. However, in my discussion below I will focus on the nutrients that are universally recognized as important for pregnancy and lactation.

4) The authors focused on prenatal supplements that had less than the recommended amount of essential nutrients. They did not ask how many of those supplements had excessive amounts of certain nutrients. In my non-systematic review of prenatal supplements, I found several that had doses of some nutrients in thousands of percent of the DV recommendations. In my opinion, this is potentially unsafe for pregnancy and nursing. I will cover this topic in more detail in my discussion.

With that in mind, here are the results of their review.

Vitamins:

When you look at vitamins that have long been recognized as essential for pregnant women, the results are encouraging:

  • Vitamin D, folate, vitamin B12, and vitamin B6 are found in adequate amounts compared to the DV in most prenatal supplements.

However, when you look at nutrients that have more recently been recognized as essential for pregnant women, the story is very different:

  • For vitamin K only 31% of prenatal supplements contain vitamin K and only 16% meet or exceed their recommendation for vitamin K.
    • Their recommendation (90 mcg/day) is identical to the DV for vitamin K. So, there is no doubt that most prenatal supplements do not provide adequate amounts of vitamin K.
  • For choline only 40 % of prenatal supplements contain choline and only 2% meet or exceed their recommendation for choline.
    • Their recommendation (350 mg/day) for choline is less than the 450 mg/day recommended by the NIH and the American College of Obstetricians and Gynecologists.
    • The average prenatal supplement only provides 25 mg of choline, which is wildly inadequate by any standard.
  • For DHA only 42% of prenatal supplements contain DHA and only 1% meet or exceed their recommendation for DHA.
    • Their recommendation (600 mg/day) for DHA is higher than the 200 – 300 mg/day recommended by the most health organizations.
    • However, the average prenatal supplement only provides 94 mg of DHA, so even at 200 – 300 mg/day a substantial percentage of prenatal supplements do not provide adequate amounts of DHA.

Minerals:

calcium supplementsThis study did not consider minerals, so I will draw on another source to estimate the adequacy of minerals in prenatal supplements.

Three key minerals for a healthy pregnancy are iron, calcium, and iodine (Yes, I realize that iodine is not a mineral, but it is usually listed with the minerals on supplement labels. And it is also essential for a healthy pregnancy). Fortunately, another recent study (LG Saldanha et al, Journal of the American Academy of Dietetics, 117: 1429-1436, 2017) looked at the adequacy of these nutrients in 214 prenatal supplements. This study found:

  • The iron DV for pregnant and lactating women is 27 mg/day and 95% of prenatal supplements contained iron at the recommended level.
  • The calcium DV for pregnant and lactating women is 1,300 mg/day. A high percentage (91%) of prenatal supplements contain calcium, but many prenatal supplements only provide 100-200 mg of calcium. That is far less than the DV.
  • The situation for iodine is even more alarming. Only 50% of prenatal supplements contain iodine. And for those that do contain iodine, the average iodine content is only 150 mcg (The DV for pregnant and lactating women is 290 mcg/day).

It is no wonder the authors of these two studies concluded that most prenatal supplements on the market do not provide adequate amounts of all the nutrients needed for a healthy pregnancy. The shortfalls are particularly acute for vitamin K, choline, DHA, iodine, and calcium.

What Should You Look For In A Prenatal Supplement?

Questioning WomanBy now you are probably wondering how you know a good prenatal supplement from a bad one. Here are six simple rules for choosing the ideal prenatal supplement.

  1. Don’t rely on health “gurus” to choose your prenatal supplement for you. I did a little “sleuthing” for you. I searched the internet for websites claiming to have identified the “best” prenatal supplements. I checked out the supplements they recommended, and here is what I found:
  • The supplements the gurus recommended checked all the boxes in that they had some of all the nutrients required for a healthy pregnancy.
  • However, the amount of those nutrients ranged from lows of 10-20% of the DV for pregnant and lactating women to thousands of percent of the DV for others.
  • In other words, they contained grossly inadequate levels of some nutrients and potentially toxic levels of others.

2) Don’t believe label claims or claims made on the manufacturer’s website. Remember the claim, “Concise prenatal formula supports both bone and brain development”, that I mentioned at the beginning of this article? The supplement associated with that claim had only 100 mg of calcium and no DHA. It is hard to imagine a supplement like that supporting either bone or brain health. The claim was bogus.

3) Don’t assume your doctor’s recommendation is the ideal prenatal supplement. A recent study (LG Saldanha et al, Journal of the American Academy of Dietetics, 117: 1429-1436, 2017) compared prescription (the kind your doctor is likely to prescribe) and non-prescription prenatal supplements. It found:

  • Compared with non-prescription supplements, prescription supplements contained significantly fewer vitamins (9 versus 11) and minerals (4 versus 8).
  • While prescription supplements contained more folic acid than non-prescription supplements, they contained significantly less vitamin A, vitamin D, iodine, and calcium.

4) Look for a prenatal supplement containing all the essential nutrients, not just those important for a healthy pregnancy. The authors of the first study made the point that most women will stop taking their regular multivitamin when they start their prenatal supplement. If that is you, your prenatal supplement should contain the nutrients you were getting from your multivitamin.

5) Look for a prenatal supplement that provide 100% of DV for all nutrients except the bulky ones. The ideal prenatal supplement should contain 100% of the DV for pregnant and lactating women for all essential nutrients. Avoid supplements with very low amounts of some nutrients and large excesses of others.

  • Bulky nutrients like calcium, magnesium, and choline are exceptions. It would be hard to get 100% DV for those nutrients in any supplement you could swallow.

6) Look for a prenatal supplement that “fills the gap” for bulky nutrients.

  • Fortunately, the NIH has estimated how much of these nutrients the average American woman gets in her diet. That allows us to estimate how much the average woman needs to get from her prenatal supplement to bring her total intake up to the DV for pregnant and lactating women. That amounts to 458 mg for calcium, 166 mg for magnesium, and 272 mg for choline.
    • That gives you a reasonable benchmark for assessing whether a prenatal supplement is providing enough of those important nutrients. When you read their labels, you will find most prenatal supplements are woefully inadequate for these nutrients.
    • You also need to ask whether your diet is “average”. For example, the average American gets 72% of their calcium from dairy foods. If you do not consume dairy, you may need to get more calcium from your supplement.

7) Avoid the excesses. Your unborn baby is precious. You don’t want to expose it to potentially toxic doses of vitamins or minerals. Avoid any prenatal supplement containing thousands of percent of the DV for some nutrients. And I would recommend caution with supplements containing over 200% of the DV for some nutrients if you are taking other supplements that may provide the same nutrient(s).

The Bottom Line 

Two recent studies have surveyed hundreds of prenatal vitamins and asked whether they provided adequate amounts of the nutrients that are essential for a healthy pregnancy. The results were shocking.

  • While most prenatal supplements provided adequate amounts of folic acid, vitamin B12, vitamin B6, vitamin D, and iron…
  • They were woefully inadequate for vitamin K, calcium, choline, iodine, and DHA – all nutrients that are essential for a healthy pregnancy.
  • Furthermore, prescription prenatal supplements (the kind your doctor is likely to prescribe) were no better than non-prescription supplements.

The authors of the first study concluded, “[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.

For more details on this study and my discussion of how you can select the ideal prenatal supplement for you and your unborn child, 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