Calcium supplements as additional source of trace elements in health and disease Part 1: adequacy and safety of chelated calcium supplements

Eleven chelated calcium supplements intended for human consumption and produced by national and multinational companies have been studied for their mineral contents. Instrumental neutron activation analysis technique was used to quantify 12 elements (As, Br, Ce, Co, Cr, Fe, K, Na, Sb, Sn, Sr and Zn) while atomic absorption spectrometry technique quantified Cd, Cu and Ni. Three different irradiation protocols were adopted using a 27 kW tank-in-pool type miniature neutron source reactor. Most of the elements were present as minor or trace constituents except for Na that was quantified as major element in CaS-1 (3.73 %), CaS-2 (1.45 %), CaS-4 (1.56 %), CaS-5 (2.31 %), CaS-6 (1.84 %), CaS-7 (1.22), CaS-8 (1.73), CaS-9 (1.94), CaS-10 (2.07) and CaS-11 (2.48). However supplement CaS-3 with Ca source of calcium acetate contained only 53 μg/g of Na and the highest amount of Fe while As, Br, Cd and Sb were not detected in this sample. Percentage daily intakes with respect to their recommended dietary reference intake s and provisional tolerable daily intakes of essential and toxic elements showed that these elements contribute to a very low percentage of the recommended/tolerable levels for most of the supplements studied. Nevertheless the findings depict that it is very important for pharmaceutical and neutraceutical firms to completely identify these elements in the supplements and include their potency on the labels before being released to the consumers.