Cadmium in zinc-containing mineral supplements.

Seven zinc-containing dietary supplements were analyzed for zinc (Zn) and cadmium (Cd) by inductively coupled plasma/mass spectrometry (ICP/MS). Cadmium was detected in all samples; however, the amount of Cd per 15 mg Zn (the daily US Recommended Dietary Allowance) varied by over 37-fold (0.039 to 1.46 micrograms Cd/15 mg Zn). Supplements with Zn in the form of a gluconate consistently contained the lowest amounts of Cd. Because Cd is a non-essential potentially toxic element for humans, its concentration in nutritional supplements should be minimized and possibly regulated by government-established standards.