Washington, DC—Recent headlines in the mainstream media are alarming:
The study, titled Content of Selected Nutrients and Potential Contaminants in Prenatal Multivitamins and Minerals: an Observational Study, was published in November 2024. The authors wrote: "Increasing consumer reliance on prenatal multivitamins and minerals (PMVMs) underscores the importance of ensuring their quality and safety. Adequate choline and iodine intakes during pregnancy are crucial for fetal development, yet discrepancies between labeled and actual content in PMVM products pose significant health risks. Additionally, the potential presence of toxic heavy metals, such as arsenic, lead, and cadmium, raises concerns about potential adverse health effects."
In conclusion, the authors said: "Current PMVM labels are misleading with the potential to harm pregnant persons and fetuses through omission or inaccurate content of essential nutrients and inclusion of heavy metals. Regulation is needed, and the Food and Drug Administration needs sufficient authority and staffing to oversee these dietary supplements."
Misapplication of USP Standards
The researchers determined that certain prenatal multivitamins contained lead, arsenic, and cadmium at levels exceeding U.S. Pharmacopeia (USP) "purity limits"—yet the Council for Responsible Nutrition (CRN) says “USP Purity Limits” is a standard that does not exist for the finished products tested in the study. CRN pointed to what it says are critical errors in the study's methodology and conclusions, which have unnecessarily alarmed pregnant women and led to misleading media coverage.
USP issued the following statement:
"A recent study published in The American Journal of Clinical Nutrition entitled “Content of Selected Nutrients and Potential Contaminants in Prenatal Multivitamins and Minerals: an Observational Study,” reported the presence of heavy metals in higher levels than those set by USP for Elemental Contaminants in Dietary Supplements. USP has determined that the limits as well as the units were incorrectly applied and that the values presented in the first publication of the study were inaccurate. USP has directly communicated with the author to clarify the correct limits and units."
As CRN explained, the referenced limits apply to ingredient testing and are measured in mcg/g, not per daily dose. Correct application of the appropriate USP standards shows that all tested products were well below established safety limits for heavy metals, CRN reported, adding that this is consistent with findings from a separate Government Accountability Office (GAO) report, which confirmed that trace amounts of heavy metals in prenatal supplements are not a health concern based on FDA metrics.
Media Reports Fuel Anxiety
“It is particularly unfortunate that it has taken a month since the study was initially released in prepublication form and a press release was issued by the author’s university to get acknowledgment that the inflammatory conclusion was in error," said CRN President & CEO Steve Mister. "During that time, numerous media have erroneously reported on the study’s conclusions in reliance on misinformation. And countless women have unnecessarily experienced anxiety over the safety of their vitamin regimens during their pregnancies.”
CRN Calls for Retraction
CRN and its members are calling on the study’s lead authors at the University of Colorado Anschutz Medical Campus, and the American Journal of Clinical Nutrition to retract the study and acknowledge the errors.
