The adult human body contains approximately 1,200 g of calcium, about 99% of which is present in the skeleton, and 20-30 g of magnesium with about 60% located in bone. The remaining 1% of total body calcium and 40% of total body magnesium are found in the soft tissues and play important roles in such vital functions as nerve conduction, muscle contraction, energy metabolism, blood clotting, membrane permeability, and hormonal signaling. Blood calcium levels are carefully maintained within very narrow limits by the interplay of several hormones (1,25-dihydroxy-cholecalciferol, parathyroid hormone, calcitonin, estrogen, and testosterone) which control calcium absorption and excretion, as well as bone metabolism. The intracellular levels of magnesium are also very tightly regulated, since their alterations can have profound effects on cardiac and skeletal muscle physiology. Bone is constantly turning over, through a continuous process of formation and resorption. In children and adolescents, the rate of formation of bone mineral predominates over the rate of resorption. In later life, resorption predominates over formation. Therefore, in normal aging, there is a gradual loss of bone. It is generally accepted that obtaining enough dietary calcium throughout life can significantly support optimal bone health. Among other factors, such as regular exercise, gender and race, calcium supplementation during childhood and adolescence appears to be a prerequisite for maintaining adequate bone density later in life. But even elderly patients can benefit significantly from supplementation with dietary calcium and magnesium.Boron is included in this formula for its supportive roles in maintaining healthy bone structure and function.