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 .
Effects of Enhanced Exercise and Combined Vitamin D and Calcium Supplementation on Muscle Strength and Fracture Risk in Postmenopausal Chinese Women.
Objective To observe the effects of enhanced exercise and combined vitamin D and calcium supplementation on muscular strength and fracture occurrence in postmenopausal women with a high risk of osteoporosis . Methods Totally 614 postmenopausal women at high risk factors of osteoporosis were enrolled in Dongcheng district of Beijing and r and omized into four groups : group A(control group , n=173),group B(regular Tai Chi exercise , n=171),group C(calcium 600 mg/d+VitD3 800 U/d , n=139 ) , and group D[calcium 600 mg/d+25 hydroxyl vitamin D(25OHD ) 0.25 μg/d , n=131].Muscular strength was measured at baseline and one and two years after intervention . Bone turnover markers were measured at baseline and during the two-year follow-up . Falls and fractures were recorded . Results The incidence of 25OHD<50 nmol/L was approximately 92.6%.During the follow-up , the left grip strength decreased significantly two years after intervention(t=-3.252,P=0.001)in group A.Right grip strength decreased significantly in group B(t=2.460,P=0.015)while left grip strength improved significantly in group C(t=-2.051,P=0.043)one year after intervention . In group D , muscular strength in both 12-month and 24-month did not change compared with baseline(both P>0.05).Furthermore , serum procollagen type I N-terminal propeptide elevated significantly in group A(t=-2.962,P=0.004),group B(t=-2.888,P=0.005 ) , and group C(t=-2.441,P=0.016),whereas β-C-terminal telopeptide of type I collagen decreased significantly in group B(t=2.285,P=0.024 ) and group D(t=2.596,P=0.011)two years after intervention . Conclusion Enhanced exercise and combined calcium vitamin D supplementation may help sustain muscle strength in postmenopausal women , while calcium and vitamin D supplementation may improve muscular strength within a short period of time
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 .