Calcium Citrate is derived from citrus fruit and contains 21% elemental calcium by weight. This formula provides Calcium in a soluble citrate form. Magnesium, Vitamin D, Boron and Zinc are added for increased assimilation. Recent research suggests that Boron may Enhance in the body’s retention of bone building minerals. Calcium is vital for the formation of strong bones and teeth and for the maintenance of healthy gums. Calcium is also important in the maintenance of a regular heart beat and in the transmission of nerve impulses.