NOVEMBER 26, 2024
As indicated in our interim alert last week, a new study published in AJCN, "Content of Selected Nutrients and Potential Contaminants in Prenatal Multivitamins and Minerals: an Observational Study,” reveals discrepancies between the labeled and actual content of choline and iodine in prenatal multivitamins and minerals (PMVMs), as well as the presence of heavy metals (lead, arsenic, and cadmium) at higher levels than purported “USP Purity Limits.” Funding for the study was provided by the Center for Science in the Public Interest (CSPI). Mainstream media interest in this study thus far has been low, except for an article in the New York Post and through syndication to some local television markets in the United States.
CRN has identified a major issue with the heavy metals testing portion of the study of which members should be aware. We were unable to locate the source of the “USP Purity Limits for Pharmaceuticals” cited in the study, and the values did not correspond to either USP General Chapter 232 Elemental Impurities-Limits or USP General Chapter 2232 Elemental Contaminants in Dietary Supplements.
CRN confirmed with a USP representative that the “USP Purity Limits for Pharmaceuticals” are incorrect. The "Purity Limits” seem to correspond to requirements for ingredient testing, not finished product limits, and the units are mcg/g, not mcg per daily dose. All products tested in the study fall below the USP limits for finished dietary supplement products as noted in the table below. The highest levels of heavy metals detected in products were 9.10 mcg/serving for arsenic; 1.26 mcg/serving for lead; 3.12 mcg/serving for cadmium. CRN is evaluating next steps to address this major error.
A table comparing the study’s “USP Purity Limits for Pharmaceuticals,” USP limits for Elemental Impurities, and USP limits for Elemental Contaminants in Dietary Supplements, as well as the daily exposure limits listed in the Government Accountability Office (GAO) report on prenatal supplements and California’s Proposition 65 “safe harbor” levels is provided below for your reference.
*0.3 mcg/kg body weight x 68 kg (150 lb) = 20.4 mcg/day
**0.21-0.36 mcg/kg body weight x 68 kg (150 lb) = 14.3-24.5 mcg/day
***Per Guidance on California Proposition 65 and Herbal Products, AHPA, August 2018 document, the MADL for arsenic as a reproductive toxicant is described as “none established.” However, the document states 10 mcg/day as the NSRL for arsenic as a carcinogen. Additional information may be found in the AHPA document.
Further, the authors acknowledge that “…this study measured total arsenic without looking at the various species of arsenic. Trivalent arsenic and inorganic arsenic compounds are many times more toxic than organic arsenic compounds such as arsenocholine which are non-toxic... All toxic and non-toxic arsenic compounds would be included in arsenic measurements. Therefore, arsenic speciation would have given more information concerning the toxicity of the arsenic in the samples.”
Summary of Study Methods and Findings
Methods:
- The study examined 47 PMVM products—32 nonprescription and 15 prescription—sourced from online and retail pharmacies.
- Only products in tablet, capsule, and gelcap form were included in the study.
- Choline and iodine quantity were measured using LC/MS/MS and ICP-MS, respectively.
- Lead, arsenic, and cadmium quantity were measured using ICP-MS.
- The average of 3 samples was used to determine the actual content.
Nutrient Results:
- None of the prescription product labels included choline.
- Choline amounts were reported on 12/32 (37.5%) of non-prescription labels. 5 (41.7%) were within 20% of the claimed amount, 2 (16.7%) were over the claimed amount by >20%, and 5 (41.7%) were under the claimed amount by >20%.
- “No product reached the adequate intake amount for choline” (450 mg/day, as established by the IOM).
- "Iodine amounts were reported on 23 of 32 (71.9%) nonprescription product labels and 2 of 15 (13.3%) of prescription product labels...19 (82.6%) were under the claimed amount by more than 20%, and none were over the claimed amount by more than 20%. Of the 2 prescription products, both were under the claimed amount by more than 20%. One nonprescription product and one prescription product contained 104 mcg/day and 74 mcg/day of iodine, respectively; however, neither product had iodine on the label."
- Iodine amounts were reported on 2/15 (13.3%) of prescription products, and both were under the claimed amount by >20%.
Heavy metals:
- Lead, arsenic, and cadmium levels were compared against the “USP Purity Limits for Pharmaceuticals.”
- "Amounts of arsenic above the USP purity limit of 2.5 mcg per serving were found in 5 (15.6%) of nonprescription products and 2 (13.3%) of prescription products."
- "Amounts of lead above the USP limit of 0.5 mcg per serving were found in 1 (3.1%) nonprescription and 1 (6.7%) prescription products."
- "Amounts of cadmium above the USP limit of 0.5 mcg per serving were found in 13 (40.6%) nonprescription products and 0 prescription products."
- Highest levels of heavy metals detected in products were 9.10 mcg/serving for arsenic; 1.26 mcg/serving for lead; 3.12 mcg/serving for cadmium.
Original Author Conclusions:
"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.”
CRN’s Conclusions:
The study's findings are flawed due to reliance on incorrect standards, misrepresentation of heavy metal levels, failure to differentiate between toxic and non-toxic forms of arsenic, and exaggeration of risks, all of which wrongly undermine consumer trust in prenatal multivitamins that play a critical role in maternal and fetal health.
CRN Guidelines for Iodine in Prenatal Multivitamin/Mineral Supplements
CRN reminds members that we established Recommended Guidelines for Iodine Quantity in Multivitamin/Mineral Supplements for Pregnancy and Lactation in 2015. These guidelines recommend that dietary supplement manufacturers and marketers should include a daily serving of at least 150 mcg of iodine in all multivitamin/mineral supplements intended for pregnant and lactating women in the U.S.
For More Information Contact: Jeff Ventura, VP of Communications, CRN at (202) 204-7680 / (202) 851-1334 (cell) or email jventura@crnusa.org