Mercury, cadmium and arsenic contents of calcium dietary supplements

Abstract

The cadmium (Cd) and arsenic (As) contents of calcium (Ca) supplements available on the Korean market were determined by a graphite furnace atomic absorption spectrometer using Zeeman background correction and peak area mode after microwave digestion. The mercury (Hg) content of the supplements was measured using an Hg analyser. Recoveries ranged from 92 to 98% for Hg, Cd and As analyses. Fifty-five brands of Ca supplements were classified into seven categories based on the major composite: bone, milk, oyster/clam shell, egg shell, algae, shark cartilage and chelated. The means of Hg, Cd and As in Ca supplements were 0.01, 0.02, and 0.48 mg kg−1, respectively. Ca supplements made of shark cartilage had the highest means of Hg (0.06 mg kg−1) and Cd (0.13 mg kg−1). The mean daily intakes of Hg and Cd from the supplement were estimated as about 0.1–0.2 μg, with both contributing less than 0.4% of provisional tolerable daily intakes set by the Food and Agricultural Organization/World Health Organization Joint Food Additive and Contaminants Committee.