Monitoring of metal and metalloid content in dietary supplements on the Croatian market

Thirty samples of widely used vitamins and herbal preparations distributed on the Croatian market were analyzed by atomic absorption spectrometry in order to estimate contamination with Pb, Cd, As, Hg, Cr, Ni and Zn due to their potential toxicity if present above the maximum allowable levels (MAL). The following concentration ranges were obtained (in μg g−1): Pb 0.25–3.86; Cd 0.05–0.28; As 0.10–0.19; Hg 0.02–0.12; Cr 0.11–64.38; Ni 0.24–338.90; and Zn 1.00–95.3. Several analyzed formulations had metal levels above the maximum allowable limits (Pb: one honey-based product and one medicinal herb-based product; Cr: one product containing vitamins; Ni: two products containing vitamins and one product of animal origin). Moreover, the estimated cumulative daily intakes of several metals from some dietary supplements were higher than the oral permitted daily exposures set by the USP Advisory Panel on metal impurities (Pb: one medicinal herb-based product; Ni: one product containing minerals and one product of animal origin). Such formulations present a significant additional source of metals in the human diet, and therefore could be harmful for human health.