Calcium Microcrystalline Hydroxyapatite, provided by Douglas Laboratories?, supplies 250 mg of elemental calcium from 1,000 mg of microcrystalline hydroxyapatite (MCHC), a bioavailable source of calcium derived from whole bone. Calcium Microcrystalline Hydroxyapatite tablets may be a useful dietary supplement for individuals who wish to increase their intake of calcium and other nutritional factors for the maintaining of healthy bone function. The adult human body contains approximately 1,200 g of calcium, about 99% of which is present in the skeleton. Bone is constantly turning over, 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. Osteoporosis, a condition of reduced bone mineral density that can increase risk of fractures, affects a large proportion of the elderly in developed countries. Caucasian and Asian women typically have low peak bone densities, and therefore, are at the greatest risk of developing osteoporosis. It is generally accepted that obtaining enough dietary calcium throughout life can significantly decrease the risk of developing osteoporosis. 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 osteoporotic patients can benefit significantly from supplementation with dietary calcium. Calcium Microcrystalline Hydroxyapatite provides a highly beneficial source of dietary calcium together with other nutrients that assist in the maintenance of healthy bone structure and function. For example, boron affects the composition, structure, and strength of bone. It appears to be necessary for calcium and magnesium absorption, their adequate renal reabsorption, and