Many OB/GYNs will tell you that it doesn't matter what brand of prenatal vitamin you buy; the important thing is that you take one before and during pregnancy to ensure you're getting adequate folic acid, DHA, and other vitamins. However, research shows that all prenatal vitamins are definitely not created equal, as certain brands can actually do more harm than good. In fact, many of these vitamins "contain harmful levels of toxic metals," according to a new study.
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Published on Nov. 19 in The American Journal of Clinical Nutrition, the study tested 47 different prescription and non-prescription prenatal vitamins "bought from online and local stores where people commonly shop," according to a press release.
The researchers checked the amounts of choline and iodine in the vitamins compared to those listed on the labels. The National Institutes of Health (NIH) states that choline is used by your brain and nervous system to help with memory, mood, and muscle control, among other things. It also helps with the formation of cell membranes. Iodine helps your body make thyroid hormones, which are needed for "proper bone and brain development during pregnancy," notes the NIH.
However, the study found that only 12 of the tested prenatal vitamins list choline as an ingredient, and only five of those "had the right amount of choline as promised on the label," states the press release. As for iodine, 25 of the tested vitamins listed it as an ingredient, but only four matched the amount on the label.
"During pregnancy, many women rely on prenatal vitamins and minerals to support their health and their baby’s development. Among the most crucial nutrients for fetal development are choline and iodine. However, some prenatal vitamins may not contain the exact amounts listed on the label and some may not contain any choline or iodine," said the study’s first author, Laura Borgelt, PharmD, MBA, professor at the University of Colorado (CU) Skaggs School of Pharmacy and Pharmaceutical Sciences at CU Anschutz.
"Our study aims to help women better understand the nutrient content in prenatal supplements, empowering them to make more informed choices and select the best options for their health and their baby's well-being," she added.
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In addition to lacking essential nutrients, many of these prenatal vitamins also contain harmful heavy metals that shouldn't be present. Thirteen of the tested supplements had cadmium levels above the purity limits set by the U.S. Pharmacopeia. Seven had too much arsenic, and two had too much lead.
"Exposure to these heavy metals in pregnancy has been associated with adverse birth outcomes," the press release states
"The presence of contaminants, especially cadmium, was also concerning. Our findings highlight a significant gap between what's listed on the labels and what’s actually in the products, underscoring the urgent need for stronger regulatory oversight in this area," Borgelt said.
She is referring to the limited scope of the U.S. Food and Drug Administration's (FDA) oversight of vitamins. The FDA must approve traditional drugs before they're sold to consumers, but this is not the case for supplements.
"Supplement companies are responsible for having evidence that their products are safe, and the label claims are truthful and not misleading," explains the NIH. "However, as long as the product does not contain a new dietary ingredient (one introduced since October 15, 1994), the company does not have to provide this safety evidence to FDA before the product is marketed."
However, the study authors still recommend taking prenatal vitamins during pregnancy. They suggest working with your healthcare provider to determine the appropriate supplement.
