World Health Day 2023: Prenatal supplements lacking correct dose for six key nutrients, study flags

07 Apr 2023 --- After analyzing 20,547 supplements on the US markets, researchers found only one product that contained target doses for six essential nutrients during pregnancy, vitamins A and D, folate, calcium, iron and omega 3. Markedly the content of omega 3 fatty acids and iron was found to have the greatest insufficiencies.

“The six nutrients we examined are vital for a healthy mom and a healthy baby,” lead author Katherine A Sauder, Ph.D. at the University of Colorado School of Medicine, tells NutritionInsight. “From a public health perspective, the healthy choice should be the easy choice, which would be one supplement with the right doses of the right nutrients.”

“We hope this study will help pregnant females get the right amounts of these nutrients, leading to healthier families. And I hope this study motivates manufacturers to make better products that truly meet the nutritional needs of pregnant females.” 

Supplements missing out on omega 3 
The target dose identified for prenatal supplements was 198 mcg retinol activity equivalents of total vitamin A, 7-91 mcg of vitamin D, 169-720 mcg dietary folate equivalents of folic acid, 383-943 mg calcium, 13-22 mg iron and at least 59 mg omega 3 fatty acids. 

The six nutrients the researchers found essential during pregnancy were vitamins A and D, folate, calcium, iron and omega 3. According to nutrition company Shaklee Corporation, up to 95% of women fail to get sufficient levels of critical nutrients that are foundational for a healthy pregnancy.

The researchers determined target doses of these nutrients needed from supplements by comparing the nutrient intake of 2,450 pregnant women from foods with recommended nutritional guidelines from the National Institutes of Health (NIH). Of the 20,547 dietary supplements analyzed, 421 were prenatal supplements. 

The researchers found that 69 products (33 prenatal) contained all six nutrients, of which seven contained target doses for five nutrients. The “missing” nutrient in many of these supplements was omega 3. 

The authors only analyzed pregnant women’s food intake to find the ideal supplement to match it, though Sauder agrees some women may take multiple supplements to meet their nutrient needs. 

“But the more pills they have to remember to take, the higher the risk of forgetting, skipping some or running out,” Sauder underscores.

“Out of all the prenatal and general vitamins analyzed, we found only one that may potentially give pregnant patients the optimal amounts of the most important nutrients. But the monthly cost of this supplement can be too high for some people and requires pregnant people to take seven pills daily.”

Implications for supplement manufacturers 
Sauder notes that the study’s results, published in the American Journal of Clinical Nutrition, indicate there’s a need for prenatal vitamin options that are low-cost and convenient and contain optimal amounts of essential nutrients. 

“Companies could study the federal recommendations for dietary intake to produce supplements with the right nutrients in the right doses to truly support healthy pregnancies.”

The researchers found that folic acid was too high in almost 60% of the prenatal supplements analyzed, while the iron content of around half also exceeded target doses.The study concludes that over 99% of all supplements on the US market lack the target dose for the six nutrients, especially in omega 3.

“Doses need to be high enough to fill the gap between what they eat and their body needs,” says Sauder. “On the other hand, unless a woman has a special medical situation, there’s generally no reason to provide two to three times (or more) the recommended dose in a supplement.”  

“For clinicians, we provided a reference table to help them evaluate the supplements recommended to pregnant patients to pick the best ones.”

Future research on other nutrients 
Sauder notes that aside from the six nutrients, future research should look at other essential nutrients for pregnancy. 

“We also need to refine our understanding of how much of these nutrients – or others we didn’t study – are needed to shift the needle on the health concerns pregnant women in the US face today. Better targets mean we can create better products.” 

She continues, “We’re now examining foods to see if there might be ‘prenatal superfoods’ that provide the right doses of these nutrients that pregnant women could add to their diet instead of a dietary supplement.”  

“We also want to understand how much of the adverse birth outcomes in this country are due to an imbalance in nutrients, so we can efficiently support women in getting the nutrition they need for a healthy pregnancy.” 

Experts flagged that taking vitamin D and fish oil during pregnancy may reduce the number of viral croup infections. Research has found that taking vitamin D during pregnancy may lower the risk of babies developing atopic eczema.

By Jolanda van Hal