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Ep. 32 – Prenatal Vitamins

On this edition of Straight Talk on Health Dr. Chet Zelasko examines a recent study on prenatal vitamins. Based on the diet of women today, what nutrient deficiencies are happening? More important, can the current crop of prenatal supplements fill in those gaps?

Welcome to Straight Talk on Health, I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the world of health. Whether it’s research that makes the news, another miracle diet, or a new food fad, I look at the science behind them, and let you know whether it’s real or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.

This research update is about a study published in one of the nutrition journals that I get every month. The results are interesting as it relates to prenatal vitamins and the availability of products to meet the needs of pregnant women. Let's look at the study.

The research question was relatively simple. Analyze pregnant women's diets at various stages during pregnancy to find out the amounts of critical nutrients needed during pregnancy that women obtained from their diet. The information showed where nutritional gaps in these women’s diet existed. Then, with that information in mind, the researchers attempted to find dietary supplements that could meet those nutrient deficiencies. The obvious outcome is to have the best of nutrients from the diet and supplements for both mother and baby to have the healthiest outcomes.

The researchers chose six nutrients with the strongest evidence for a potential benefit for maternal-child health outcomes: vitamin A, vitamin D, folate/folic acid, calcium, iron, and ω-3 FAs. The goals were to provide target doses for supplementation of these key nutrients. Concurrent with that, they wanted to generate a list of products currently available in the US that provide these target doses. You might think that there would many dietary supplements, including those prescribed by physicians and only available through pharmacies, that that would fit the nutritional gaps in the diet. There are not. Let’s look at why.

The research group contained 2450 subjects; these were taken from six different groups across five different states. They used the best nutritional intake techniques available: 24-hour dietary recall with an interview in most cases. They did not use supplement intake at this point because they wanted to see how much nutrition women got from their diet alone during pregnancy.

The researchers chose 50% of the adequate intake of nutrients as a target. The greatest risk of inadequate intake was for vitamin D and iron with over 80% of women of all ages not obtaining those nutrients from their diet. Omega-3s were close to 70% inadequate, calcium was deficient in younger women at over 50% versus 30% for older women, folate/folic acid close to 45% for younger women versus 34% of older subjects, and finally vitamin A (that included beta-carotene) with over 40% of younger women at risk for deficiency and only 24% for older women. Any way you look at it, women were not getting enough nutrients from their diet.

Now came the fun parts so to speak. Finding a dietary supplement that would provide adequate amounts of all the nutrients that women were not getting from their diet. The National Institutes of health maintains a database called the Dietary Supplement Label Database. As of this recording there were over 156,000 current and prior supplement labels listed for dietary supplements of all kinds.

But in order to qualify as a pre-natal to meet nutritional needs during pregnancy, the researchers determined the supplement must contain at least the following:

198 micrograms of vitamin A or vitamin A activity

7 to 91 micrograms of vitamin D

169 to 720 micrograms of total folate/folic acid activity

383 to 943 milligrams of calcium

13 to 22 milligrams of iron

>59 milligrams of omega-3 fatty acids

Whether categorized as a prenatal or as a regular supplement, there was only one that was considered to be adequate but judged to be too expensive for all economic brackets. That means that there were no complete prenatal vitamins available in the dietary supplement marketplace. It would take more than one product to get the adequate intake as determined by this large study. This led the researchers to say that a large US dietary supplement market is not meeting the nutrient needs of pregnant women.

Not so fast. The medical profession, led by the pharmaceutical industry, is also not meeting the needs of women. DailyMed, maintained by the National Library of Medicine. Is a database of all pharmaceuticals. It contains over 144,000 pharmaceuticals for humans and animals. That includes prenatal vitamins. You can see the labels of every prenatal made by the pharmaceutical industry. The researchers found that they do not meet the adequate intake either.

They concluded that nearly all pregnant women were at risk of inadequate intake of one or more key nutrients from foods alone. Therefore, they need to supplement their diet from dietary supplements. However, those supplements have to be chosen carefully based on diet and in discussion with their healthcare professionals. The research also showed that some supplements may contain too much preformed vitamin A, which has an Upper Limit. However, beta-carotene, as a pro-vitamin A, has no such restriction. They called for the supplement industry to develop products that maximize the number of pregnant women receiving enough (but not too much) vitamin A, vitamin D, folic acid, calcium, iron, and ω-3 FAs.

Seems simple enough but the problem while seemingly simple is complex. There are restrictions on what dietary supplements can say about treating diseases and conditions. While certainly not a disease, pregnancy does fall into a category of patients that are under doctor’s care. There may be limitations on what claims could be made about filling the nutritional gaps during pregnancy which could lead to confusion.

What further complicates things is that there are pre-natal vitamins that are sold via prescription made by pharmaceutical companies. Those are not approved by the FDA either because there are no clinical trials to support the efficacy of the product. They’ve never been tested in clinical trials. Further, having seen the label of those prescription prenatal supplements, they do not meet the standards of the critical nutrients in this study either.

I don't like to leave you're hanging. The best recommendations I can give you is this. Most importantly, eat the healthiest diet that you can afford. Focus on fruits, vegetables, whole grains, using cold water fish and nuts as sources of omega-3 fatty acids. Reducing intake of refined carbohydrates is always a good idea while increasing protein can be beneficial. Finally, discuss your supplement needs with your healthcare professional. There no single product that can meet the complete needs of women during pregnancy. However, this latest research can certainly point all parties in the right direction to get the critical nutrients for healthy moms and healthy babies.

Dr. Chet Zelasko is a scientist, speaker, and author. Dr. Chet has a Ph.D. and MA in Exercise Physiology and Health Education from Michigan State University and a BS in Physical Education from Canisius College. He’s certified by the American College of Sports Medicine as a Health and Fitness Specialist, belongs to the American Society of Nutrition, and has conducted research and been published in peer-reviewed journals. You can find him online at drchet.com.
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