[Prevention of osteoporosis by foods and dietary supplements. Magnesium and bone metabolism].

About half the total magnesium (Mg) of the body is existed in bone. Bone is one of the main Mg pools in the body. Epidemiologic studies have demonstrated a positive correlation between Mg intake and bone mineral density. It is also reported that Mg deficiency induced a decrease in osteoblasts number, an increase in osteoclasts number and a decrease in bone strength in rats. In contrast, dietary Mg supplementation improved bone formation, bone resorption and bone strength in ovariectomized rats. Mg deficiency is known as a risk factor for osteoporosis, since Mg is essential mineral for normal bone growth. However, the detail of effects of Mg on bone metabolism remains unclear. Further studies should be developed to clarify the details.