Calcium supplements  increased BMD by 0.7 - 1.8 % at all five skeletal sites at one , two , and over two and a half years , but the size of the increase in BMD at later time points was similar to the increase at one year .
Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD , which are unlikely to lead to a clinical ly significant reduction in risk of fracture
OBJECTIVE To determine whether increasing calcium intake from dietary sources affects  bone mineral density ( BMD ) and , if so , whether the effects are similar to those of calcium supplements .
Effects of calcium supplementation on clinical fracture and bone structure: results of a 5-year, double-blind, placebo-controlled trial in elderly women.
BACKGROUND Increased dietary calcium intake has been proposed as a population -based public health intervention to prevent osteoporotic fractures . We have examined whether calcium supplementation decreases clinical fracture risk in elderly women and its mechanism of action . METHODS Five-year , double-blind , placebo-controlled study of 1460 women recruited from the population and older than 70 years ( mean age , 75 years ) who were r and omized to receive calcium carbonate , 600 mg twice per day , or identical placebo .  The primary end points included clinical incident osteoporotic fractures , vertebral deformity , and adverse events ascertained in 5 years . Bone structure was also measured using dual x-ray absorptiometry of the hip and whole body , quantitative ultrasonography of the heel , and peripheral quantitative computed tomography of the distal radius . RESULTS Among our patients , 16.1 % sustained 1 or more clinical osteoporotic fractures . In the intention-to-treat analysis , calcium supplementation did not significantly reduce fracture risk ( hazard ratio , 0.87 ; 95 % confidence interval , 0.67 - 1.12 ) . However , 830 patients ( 56.8 % ) who took 80 % or more of their tablets ( calcium or placebo ) per year had reduced fracture incidence in the calcium compared with the placebo groups ( 10.2 % vs 15.4 % ; hazard ratio , 0.66 ; 95 % confidence interval , 0.45 - 0.97 ) . Calcium-treated patients had improved quantitative ultrasonography findings of the heel , femoral neck and whole-body dual x-ray absorptiometry data , and bone strength compared with placebo-treated patients . Of the 92 000 adverse events recorded , constipation was the only event increased by the treatment ( calcium group , 13.4 % ; placebo group , 9.1 % ) . CONCLUSION Supplementation with calcium carbonate tablets supplying 1200 mg/d is ineffective as a public health intervention in preventing clinical fractures in the ambulatory elderly population owing to poor long-term compliance , but it is effective in those patients who are compliant
Calcium supplements  increased BMD by 0.7 - 1.8 % at all five skeletal sites at one , two , and over two and a half years , but the size of the increase in BMD at later time points was similar to the increase at one year .
Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD , which are unlikely to lead to a clinical ly significant reduction in risk of fracture
OBJECTIVE To determine whether increasing calcium intake from dietary sources affects  bone mineral density ( BMD ) and , if so , whether the effects are similar to those of calcium supplements .