Lead in Mineral or Multivitamin-Multimineral Products.

Abstract

Assess the current daily interim reference level of lead and the amount contained in current mineral and multivitamin-multimineral (MVM) products. PubMed search from 1980 to May 15, 2021, limited to the English language, via the search strategy ((mineral OR multivitamin OR calcium OR iron OR magnesium OR copper OR zinc OR chromium OR selenium) AND (heavy metals OR Pb OR lead)). Narrative review of studies assessing lead content in mineral or MVM products. Products containing different calcium forms (dolomite, bone meal, natural carbonate) have historically had higher lead levels than others (refined carbonate, lactate, gluconate, acetate, sevelamer), but the gap has closed considerably since the year 2000. Although only limited assessments of magnesium and zinc supplements have been conducted, no alarming average lead amounts were found. MVM products assessed since 2007 had low median or mean lead concentrations. However, large interproduct differences exist, with many products having very little lead and some products having concerning amounts. It is difficult for pharmacists and consumers to know the amount of lead in an actual product unless it is tested in an independent third-party lab. The United States Pharmacopeia and NSF International will provide a seal on the products stating that the products have a low level of lead, but even so, children could receive more lead than the Food and Drug Administration's Interim Reference Level. The threat from lead exposure in mineral and MVM products have diminsihed considerably over time but some products can still have excessive amounts. Without third-party testing, it is difficult for clinicians and consumers to know which outlier products to avoid.