CONCLUSIONS Dietary calcium intake is not associated with risk of fracture , and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures .
OBJECTIVE To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures .
Effect of calcium supplementation on bone loss in postmenopausal women.
BACKGROUND The use of calcium supplements slows bone loss in the forearm and has a beneficial effect on the axial bone density of women in late menopause whose calcium intake is less than 400 mg per day . However , the effect of a calcium supplement of 1000 mg per day on the axial bone density of postmenopausal women with higher calcium intakes is not known . METHODS We studied 122 normal women at least three years after they had reached menopause who had a mean dietary calcium intake of 750 mg per day . The women were r and omly assigned to treatment with either calcium ( 1000 mg per day ) or placebo for two years . The bone mineral density of the total body , lumbar spine , and proximal femur was measured every six months by dual-energy x-ray absorptiometry .  Serum and urine indexes of calcium metabolism were measured at base line and after 3 , 12 , and 24 months . RESULTS The mean ( + /- SE ) rate of loss of total-body bone mineral density was reduced by 43 percent in the calcium group ( -0.0055 + /- 0.0010 g per square centimeter per year ) as compared with the placebo group ( -0.0097 + /- 0.0010 g per square centimeter per year , P = 0.005 ) . The rate of loss of bone mineral density was reduced by 35 percent in the legs ( P = 0.02 ) , and loss was eliminated in the trunk ( P = 0.04 ) . Calcium use was of significant benefit in the lumbar spine ( P = 0.04 ) , and in Ward 's triangle the rate of loss was reduced by 67 percent ( P = 0.04 ) . Calcium supplementation had a similar effect whether dietary calcium intake was above or below the mean value for the group . Serum parathyroid hormone concentrations tended to be lower in the calcium group , as were urinary hydroxyproline excretion and serum alkaline phosphatase concentrations . CONCLUSIONS Calcium supplementation significantly slowed axial and appendicular bone loss in normal post-menopausal women
CONCLUSIONS Dietary calcium intake is not associated with risk of fracture , and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures .
OBJECTIVE To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures .