The Council for Responsible Nutrition (CRN) responded to a study from The American Journal of Clinical Nutrition that reported certain prenatal vitamins contained heavy metals such as lead, arsenic and cadmium.
The study, which was published on Nov. 18, 2024, inaccurately reported these multivitamins exceeded “USP Purity Limits,” a standard that does not apply to the finished products in the study.
In a statement, The U.S. Pharmacopeia (USP) said “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.”
According to CRN, the referenced limits pertain to ingredient testing and are measured in mcg/g not per daily dosage. Correct application of USP standards shows the tested products were below established safety limits for heavy metals. This is consistent with a separate report from the Government Accountability Office (GAO) which confirmed “trace amounts of heavy metals in prenatal supplements are not a health concern based on FDA metrics.”
CRN said the study’s dissemination, an accompanying press release and subsequent media coverage had led to “needless alarm” from pregnant women. Headlines in major outlets are based on the flawed application of USP standards and “misrepresent the safety of these critical products.”
“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 acknowledgement that the inflammatory conclusion was in error,” said Steve Mister, president and CEO of CRN. “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.”
For more information, visit www.crnusa.org or www.usp.org.
