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 .
Optimum dose of vitamin D for disease prevention in older people: BEST-D trial of vitamin D in primary care
Summary This trial compared the effects of daily treatment with vitamin D or placebo for 1 year on blood tests of vitamin D status . The results demonstrated that daily 4000 IU vitamin D3 is required to achieve blood levels associated with lowest disease risks , and this dose should be tested in future trials for fracture prevention . Introduction The aim of this trial was to assess the effects of daily supplementation with vitamin D3 4000 IU ( 100 μg ) , 2000 IU ( 50 μg ) or placebo for 1 year on biochemical markers of vitamin D status in preparation for a large trial for prevention of fractures and other outcomes . Methods This is a r and omized placebo-controlled trial in 305 community-dwelling people aged 65 years or older in Oxfordshire , UK . Outcomes included biochemical markers of vitamin D status ( plasma 25-hydroxy-vitamin D [ 25[OH]D ] , parathyroid hormone [ PTH ] , calcium and alkaline phosphatase ) , cardiovascular risk factors and tests of physical function . Results Mean ( SD ) plasma 25(OH)D levels were 50 ( 18 ) nmol/L at baseline and increased to 137 ( 39 ) , 102 ( 25 ) and 53 ( 16 ) nmol/L after 12 months in those allocated 4000 IU , 2000 IU or placebo , respectively ( with 88 % , 70 % and 1 % of these groups achieving the pre-specified level of > 90 nmol/L ) . Neither dose of vitamin D3 was associated with significant deviation outside the normal range of PTH or albumin-corrected calcium . The additional effect on 25(OH)D levels of 4000 versus 2000 IU was similar in all subgroups except for body mass index , for which the further increase was smaller in overweight and obese participants compared with normal-weight participants . Supplementation with vitamin D had no significant effects on cardiovascular risk factors or on measures of physical function . Conclusions After accounting for average 70 % compliance in long-term trials , doses of 4000 IU vitamin D3 daily may be required to achieve plasma 25(OH)D levels associated with lowest disease risk in observational studies
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 .