Advances in Effects of Cadmium on Calcium Metabolism and Its Associated Potential Mechanisms

Cadmium targets on kidney and bone and results in many toxic effects. Disturbance of calcium metabolism is one of the important aspects of cadmium toxicity, which includes reduced intestinal calcium absorption, increased urinary calcium excretion, negative calcium balance, development of osteomalacia and osteoporosis. There exists two potential mechanism of influence of cadmium on calcium metabolism. One is the direct inhibition of cadmium on active transports of calcium. The other is the indirect influence on calcium metabolism due to reduced renal synthesis of 1,25-dihydroxycholesterol induced by cadmium. Further research should focus on revealing how cadmium directly inhibits calcium entering into cells and transporting by calcium binding protein, elucidating whether renal synthesis of 1,25-dihydroxycholesterol is reduced in low-level cadmium exposure population, and also on clarifying the molecular biological mechanism of effects of cadmium on calcium metabolism.