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. 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. Intestinal calcium absorption ranges from 15 to 75% of ingested calcium. Vitamin D is a key regulatory hormone for calcium and bone metabolism. Adequate vitamin D status is essential for ensuring normal calcium absorption and maintenance of healthy calcium plasma levels. Numerous scientists now feel that supplementation with vitamin D at levels greater than previously thought necessary is critical to helping maintain healthy bone remodeling and healthy vitamin D plasma levels. Magnesium absorption is independent of vitamin D status and ranges from 30 to 60% of ingested magnesium. It is generally accepted that obtaining enough dietary calcium throughout life may increase bone mineral density. 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. Dyna-Cal 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 their incorporation into the bone matrix. Boron is absorbed at about 90% efficiency and is rapidly distributed among the tissues.