The U.S. Food and Drug Administration risk assessment on lead in women's and children's vitamins is based on outdated assumptions.

摘要

BACKGROUND: Following a recent report of lead in certain commercial vitamin products, the U.S. Food and Drug Administration (FDA) conducted a nationwide survey to determine the Pb content in 324 multivitamin/mineral products labeled for use by women and children. The FDA compared estimated Pb exposures from each product with safe/tolerable exposure levels, termed provisional total tolerable intake (PTTI) levels, previously developed for at-risk population groups in 1992. OBJECTIVE: We investigated the FDA's conclusions that Pb concentrations in all vitamin products examined do not pose a hazard to health because they are below the PTTI levels for all groups considered. DISCUSSION: For their initial estimations of PTTI levels, the FDA used a blood lead level (BLL) of 10 microg/dL as the threshold for adverse effects in children and in pregnant or lactating women. Studies have repeatedly linked chronic exposure to BLLs < 10 microg/dL with impairments in cognitive function and behavior in young children despite the absence of overt signs of toxicity. The FDA analysis also omitted any consideration of nonfood sources of Pb exposure, which is inconsistent with our current understanding of how most children develop elevated BLLs. CONCLUSION: We feel that based on these oversights, the FDA's conclusions are unduly reassuring and that reconsideration of their current recommendations appears warranted.