Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .
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
Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .