Jan. 12, 2024 – The labels on prenatal supplements, commonly taken by people during pregnancy to promote maternal and fetal health, often misstate the amount of nutrients the product contains, according to a government report released Thursday.
Experts from the Government Accountability Office (GAO), a nonpartisan government agency providing fact-based information to Congress, found that 11 of the 12 over-the-counter supplements tested had at least one nutrient above or below the levels noted on the labels.
Of the 11 that had nutrients above or below the levels on the label, one product had an average amount of folic acid that “may cause a health concern based on metrics established by the Institute of Medicine [now the National Academy of Medicine],” the report said.
Based on the findings, the GAO recommends Congress strengthen the FDA’s oversight of dietary supplements, which are now regulated not as drugs but as foods. Under the Dietary Supplement Health and Education Act of 1994, the FDA does not have the authority to approve dietary supplements before they are sold. It can restrict or recall products on the market if problems occur.
The agency will not publicly release the names of the brands it tested, said Karen L. Howard, PhD, director of science and technology assessment for the GAO, who led the study. The agency did release the full list of brands and the full test results to the FDA, she said.
For the analysis, the GAO contracted with an accredited laboratory to test the 12 prenatal supplements chosen. The analysis evaluated levels of folic acid, iodine, iron, and vitamins A, C, and E.
Other than folic acid, the other tested products did not contain average amounts of nutrients likely to be a health concern, the report said.
Of the six nutrients, the level of vitamin E varied the most among the products tested, with a range of 28% to 332% of the amount stated on the label. Vitamin A was most frequently found in amounts outside the acceptable deviations from the label value, found in nine of the 12 supplements.
The experts also tested the supplements for heavy metals such as arsenic, cadmium, lead, and mercury. There were trace amounts of lead or cadmium in half of the products, but not in amounts likely to be a health concern, according to the report.
Because no federal statutory definition exists for what a prenatal supplement is and what it should contain, makers are free to decide which nutrients to include and what amounts, Howard said. The benchmark used for the study was a voluntary guideline from the Institute of Medicine (National Academy of Medicine) as the “tolerable upper intake level.”
The FDA might consider requiring manufacturers to notify or register with the agency before marketing a product and providing a copy of the label, the report recommended.
The GAO did the research at the request of U.S. Sen. Jon Ossoff, D-GA, chair of the Subcommittee on Human Rights and Law, part of the Senate Judiciary Committee, who has backed other measures to improve maternal health.
The findings are “concerning,” said Christopher Zahn, MD, interim CEO and chief of clinical practice and health equity and quality for the American College of Obstetricians and Gynecologists. “The GAO report is a powerful example of why ACOG supports increased FDA oversight and the standardization and regulation that’s needed to make sure prenatal vitamins and supplements are safe and accurately labeled.”
Even so, he said, the college continues to recommend the supplements, especially folic acid, which reduces the risk of brain and spinal cord defects.
Keeping perspective is important, said Jeff Ventura, a spokesperson for the Council for Responsible Nutrition, a trade association for the dietary supplement industry. “It’s important to keep in mind this is one product [with a potential health concern], and exceeding (Institute of Medicine’s) upper level threshold slightly does not necessarily mean the product poses a health risk. Whether too much folic acid poses a health risk is dependent on innumerable variables, up to and including personal physiology.”
The group supports the idea of more government oversight, including having supplement makers list their products with the FDA.
“This [report] speaks to the unregulated nature of the supplement industry, even for prenatal vitamins,” said Jeffrey Linder, MD, MPH, chief of general internal medicine and a professor of medicine at Northwestern University Feinberg School of Medicine, who has written about dietary supplements.
He said the report is a reminder that “we should be skeptical of what we’re being sold.”
Misconceptions about supplements are common among the public, he said. He reminds people: “These products are not required to be evaluated by the FDA or any regulatory body before being sold, as long as they adhere to labeling requirements, including that they say any health claims have not been evaluated by the Food and Drug Administration and they are not intended to diagnose, treat, cure, or prevent any disease.”
Advice for Consumers
Prenatal vitamins are recommended during pregnancy by the American College of Obstetricians and Gynecologists and others to make up for the average diet not supplying adequate amounts of nutrients.For example, pregnant people need 600 micrograms of folic acid per day, the group says. Because it is difficult to get this much from food alone, a daily prenatal with at least 400 milligrams is recommended starting at least a month before pregnancy, if possible, and during the first 12 weeks of pregnancy.
The CDC recommends all women of reproductive age take 400 milligrams of folic acid daily.
Pregnant people should talk to their health care provider before buying prenatal supplements, Howard said. As for looking into prenatal vitamins provided by prescription, “Prescription prenatal supplements are in the same FDA category as over-the-counter supplements and are regulated the same,” she said.