Bone loss appears to begin about age 35 and if of special concern to women. Lack of exercise and decreased secretion of the hormone estrogen after menopause have been related to calcium loss. A calcium loss is only visible in X-rays after the loss is acute. It is estimated that up to 60 percent of the mineral content of bone may be gone before the loss can be detected. Physical activity helps to increase bone volume and density.
Weight control can also take some strain off bones and muscles so they can perform better.
Of course, the structural system requires a balanced diet with a healthy supply of minerals. The word bone was derived from a Greek word meaning dried up, but bone is anything but dried up. In fact, about one-third of bone's composition is water. Bone is biologically active, and millions of red blood cells are manufactured in the bone marrow, the soft inner core. Internal bone structure is made up of collagen, from Greek words meaning glue forming.