For hip fracture , at a 15 % relative risk , the effect estimate lay between the futility boundary and the inferior boundary , meaning there is reliable evidence that vitamin D supplementation does not reduce hip fractures by this amount , but uncertainty remains as to whether it might increase hip fractures .
The effect estimate lay within the futility boundary at thresholds of 0·5 % for total hip , forearm , and total body bone mineral density , and 1·0 % for lumbar spine and femoral neck , providing reliable evidence that vitamin D does not alter these outcomes by these amounts .
INTERPRETATION Our findings suggest that vitamin D supplementation does not prevent fractures or falls , or have clinical ly meaningful effects on bone mineral density .
There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health .
BACKGROUND The effects of vitamin D on fractures , falls , and bone mineral density are uncertain , particularly for high vitamin D doses .
We aim ed to determine the effect of vitamin D supplementation on fractures , falls , and bone density .
A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas.
BACKGROUND Epidemiologic and pre clinical data suggest that higher intake and serum levels of vitamin D and higher intake of calcium reduce the risk of colorectal neoplasia . To further study the chemopreventive potential of these nutrients , we conducted a r and omized , double-blind , placebo-controlled trial of supplementation with vitamin D , calcium , or both for the prevention of colorectal adenomas . METHODS We recruited patients with recently diagnosed adenomas and no known colorectal polyps remaining after complete colonoscopy . We r and omly assigned 2259 participants to receive daily vitamin D3 ( 1000 IU ) , calcium as carbonate ( 1200 mg ) , both , or neither in a partial 2 × 2 factorial design . Women could elect to receive calcium plus r and om assignment to vitamin D or placebo . Follow-up colonoscopy was anticipated to be performed 3 or 5 years after the baseline examinations , according to the endoscopist 's recommendation . The primary end point was adenomas diagnosed in the interval from r and omization through the anticipated surveillance colonoscopy . RESULTS Participants who were r and omly assigned to receive vitamin D had a mean net increase in serum 25-hydroxyvitamin D levels of 7.83 ng per milliliter , relative to participants given placebo . Overall , 43 % of participants had one or more adenomas diagnosed during follow-up . The adjusted risk ratios for recurrent adenomas were 0.99 ( 95 % confidence interval [ CI ] , 0.89 to 1.09 ) with vitamin D versus no vitamin D , 0.95 ( 95 % CI , 0.85 to 1.06 ) with calcium versus no calcium , and 0.93 ( 95 % CI , 0.80 to 1.08 ) with both agents versus neither agent . The findings for advanced adenomas were similar . There were few serious adverse events . CONCLUSIONS Daily supplementation with vitamin D3 ( 1000 IU ) , calcium ( 1200 mg ) , or both after removal of colorectal adenomas did not significantly reduce the risk of recurrent colorectal adenomas over a period of 3 to 5 years . ( Funded by the National Cancer Institute ; Clinical Trials.gov number , NCT00153816 . )
For hip fracture , at a 15 % relative risk , the effect estimate lay between the futility boundary and the inferior boundary , meaning there is reliable evidence that vitamin D supplementation does not reduce hip fractures by this amount , but uncertainty remains as to whether it might increase hip fractures .
The effect estimate lay within the futility boundary at thresholds of 0·5 % for total hip , forearm , and total body bone mineral density , and 1·0 % for lumbar spine and femoral neck , providing reliable evidence that vitamin D does not alter these outcomes by these amounts .
INTERPRETATION Our findings suggest that vitamin D supplementation does not prevent fractures or falls , or have clinical ly meaningful effects on bone mineral density .
There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health .
BACKGROUND The effects of vitamin D on fractures , falls , and bone mineral density are uncertain , particularly for high vitamin D doses .
We aim ed to determine the effect of vitamin D supplementation on fractures , falls , and bone density .