METABOLIC BALANCES OF CADMIUM, COPPER, MANGANESE, AND ZINC IN MAN

Balance studies of cadmium, copper, manganese, and zinc were carried out under constant dietary conditions in eight adult males during two calcium intake levels of 200 and 800 mg/day and in an additional single case during a calcium intake of 1500 mg/day. The dietary content and the excretions of these elements in urine and stool were determined. The mean dietary content of cadmium was 32.9 μg/day, of copper 1020 μg/day, of manganese 2130 μg/day, and of zinc 12.4 mg/day. The ratio of the fecal/urinary cadmium excretion was approximately 1.5 and the main pathway of excretion of the other three elements was via the intestine, while the urinary excretions were very low. The different trace element balances were eighter slightly negative or in equilibrium, except that the zinc balances were positive in 50% of the cases. All balances should be considered maximal values, as the losses in sweat were not determined. The calcium intake level had little effect on the excretion and retention of these trace elements.