Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment .
REVIEW ER 'S CONCLUSIONS Calcium supplementation alone has a small positive effect on bone density .
The data show a trend toward reduction in vertebral fractures , but it is unclear if calcium reduces the incidence of non vertebral fractures
BACKGROUND Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy ( Kanis 1989 ; Nordin 1990 ) .
The Food and Drug Administration in the US has permitted a bone health cl aim for calcium-rich foods , and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis .
OBJECTIVES To assess the effects of calcium on bone density and fractures in postmenopausal women .
Long-term effects of calcium supplementation on serum parathyroid hormone level, bone turnover, and bone loss in elderly women.
We report a 4-year r and omized , double-blind , placebo-controlled clinical trial in 236 normal postmenopausal women ( mean age + /- SE , 66.3+/-0.2 years ) who were r and omized to a calcium ( 1600 mg/day as the citrate ) or placebo group .  The women were seen every 6 months ; 177 completed the trial . Net percentage changes in each group are given relative to baseline . The differences in net percentage changes ( calcium group minus placebo group ) in medians were : for lumbar spine bone density , 2.0 % ( p < 0.001 ) at year 1 and 0.3 % ( not significant ) at year 4 ; for proximal femur bone density , 1.3 % ( p = 0.003 ) at year 1 and 1.3 % ( p = 0.015 ) at year 4 ; and for total body bone mineral , 0.4 % ( p = 0.002 ) at year 1 and 0.9 % ( p = 0.017 ) at year 4 . Similar differences at year 4 were : -18.9 % ( p = 0.002 ) for parathyroid hormone ( PTH ) , -11.9 % ( p = 0.026 ) for serum osteocalcin , and -32.2 % ( p = 0.003 ) for urine free pyridinoline . We conclude that long-term administration of calcium supplements  to elderly women partially reverses age-related increases in serum PTH level and bone resorption and decreases bone loss . However , the effects on bone loss were weaker than those reported for estrogen , bisphosphonates , or calcitonin therapy , indicating that calcium supplements alone can not substitute for these in treating established osteoporosis . Nonetheless , because of their safety , high tolerance , and low expense , calcium supplements may be a useful preventive measure for elderly postmenopausal women whose bone mineral density values are normal for their age
Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment .
REVIEW ER 'S CONCLUSIONS Calcium supplementation alone has a small positive effect on bone density .
The data show a trend toward reduction in vertebral fractures , but it is unclear if calcium reduces the incidence of non vertebral fractures
BACKGROUND Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy ( Kanis 1989 ; Nordin 1990 ) .
The Food and Drug Administration in the US has permitted a bone health cl aim for calcium-rich foods , and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis .
OBJECTIVES To assess the effects of calcium on bone density and fractures in postmenopausal women .