Calcium is an indispensably important element for human bodies.The functioning mechanism of calcium is rather complicated and despite a large amount of domestic and foreign researches carried out in these years have proved the moderating effect of calcium on the normal physiological functions of various body systems

many questions remained to be solved

and controversial opinions still exist as to calcium deficiency in human bodies and how to supplement calcium safely.This article adopts the means of general discussion and summarizes domestic and foreign researches of recent years on controversies surrounding calcium′s functioning mechanism and calcium supplementation

and discusses about safe means for calcium supplementation as well as the choosing of calcium enhancing medicament in an expectation of providing basis to the general public for a correct understanding of calcium.