Almost no US supplements provide key nutrients in doses needed for pregnancy: Study

After analyzing over 20,000 dietary supplements, researchers found only one that met the nutritional recommendations for pregnancy for vitamin A, vitamin D, folic acid, calcium, iron, and omega-3 fatty acids when used to supplement the participants' diets, according to a new study.

The aim of this collaborative research study was to identify six key prenatal nutrients that pregnant women should consume from dietary supplements to bridge the gap between food-based intake and estimated requirement. These nutrients were determined by their strongest evidence for a potential benefit for maternal-child health outcomes: Vitamin A, vitamin D, folate/folic acid, calcium, iron, and ω-3 FAs.

Analysis of products listed in the NIH Dietary Supplement Label Database revealed 20,547 products that contained at least one of the key nutrients; of which 421 were labeled as prenatal products. Of the 20,547 products, 69 (0.3%; 33 prenatal (0.3%) contained all 6 nutrients, but only one (0.005%; not a prenatal) contained target doses of all six key nutrients.

Researchers led by Katherine Sauder, PhD, from the University of Colorado, also analyzed dietary intakes from 2,450 pregnant women participating in the NIH Environmental influences on Child Health Outcomes (ECHO) program from 2007 to 2019.

Writing in The American Journal of Clinical Nutrition, Dr Sauder and her co-authors reported that nearly all pregnant participants were at risk of inadequate dietary intake of at least one key nutrient from food alone.

The risk of inadequate intake was the greatest for vitamin D and iron (83%–96% at risk for both age groups), followed by ω-3 FAs (67% of younger participants at risk and 50% of older participants at risk), calcium (55%of younger participants at risk and 30% of older participants at risk), folate/folic acid (45% of younger participants at risk and 34% of older participants at risk), and then vitamin A (42% of younger participants at risk and 26% of older participants at risk).

Sauder et al. concluded that at present, “the US dietary supplement market is not meeting nutrient needs of pregnant females.”

Takeaways

Adequate food and nutrient intake during pregnancy is universally recognized as optimal for fetal development and maternal health. According to USDA data, many who are pregnant are not meeting recommendations for certain food groups and specific nutrients beneficial for maternal-child health outcomes, so it’s generally recommended for those populations to take a daily prenatal supplement.

Most healthcare providers who care for women during pregnancy are ill prepared to analyze dietary intake information and provide appropriate advice to women when dietary inadequacies are identified. Everyone has different needs, baseline nutrient levels and absorption capabilities. Healthcare providers prescribe a “default” dietary supplement or give general advice for patient self-selection.

Commenting on the study’s findings, Dr Duffy MacKay, SVP, Dietary Supplements, at the Consumer Healthcare Products Association (CHPA), told us: “This study recognizes the essential role dietary supplements play in filling nutrient shortfalls during pregnancy, but it fails to recognize the diversity of people’s diets, and why a universal pre-natal supplement might not be the best choice for some women.”

Dr. Susan Mitmesser, PhD, Pharmavite’s VP of Science & Technology, noted, “Currently, there is no standard formula for prenatal supplements." While there are RDA (Recommended Dietary Allowance) and UL (Tolerable Upper Intake Levels) established, there is no definition or standard of what nutrients a prenatal supplement must contain, and at what levels, she explained.

Formalization of a standard prenatal supplement poses significant challenges. There are “a host of valid scientific, technical, and safety reasons as to why the six key nutrients selected by the researchers of this study are not combined into one single pre-natal product,” said Dr MacKay. He added supplemental recommendations should be based on the individual’s unique health situation.

These findings highlight the need to challenge the assumption that one diet and one supplement fits all. Whether it's using nutrigenomic-based approaches to individualize nutrition recommendations, biochemical markers to assess individual nutritional status or the rise in research on the gut microbiome and maternal and infant health, the opportunities for a personalized approach to supplementation are vast.

Source: The American Journal of Clinical Nutrition
Volume 117 (2023) 823–829 / doi: 10.1016/j.ajcnut.2022.12.018
"Selecting a Dietary Supplement with Appropriate Dosing for Six Key Nutrients in Pregnancy"
Authors: Sauder, C. et al.