Recent meta-analyses reinforce the finding that 10 - 20 μg per day of vitamin D can reduce all-cause mortality and cancer mortality in middle-aged and older people .
Although vitamin D doses were greater than those assessed in the past , we found no new evidence that supplementation could have an effect on most non-skeletal conditions , including cardiovascular disease , adiposity , glucose metabolism , mood disorders , muscular function , tuberculosis , and colorectal adenomas , or on maternal and perinatal conditions .
The compilation of results from 83 trials showed that vitamin D supplementation had no significant effect on biomarkers of systemic inflammation .
The main new finding highlighted by this systematic review is that vitamin D supplementation might help to prevent common upper respiratory tract infections and asthma exacerbations .
There remains little evidence to suggest that vitamin D supplementation has an effect on most conditions , including chronic inflammation , despite use of increased doses of vitamin D , strengthening the hypothesis that low vitamin D status is a consequence of ill health , rather than its cause .
We further hypothesise that vitamin D supplementation could exert immunomodulatory effects that strengthen resistance to acute infections , which would reduce the risk of death in debilitated individuals .
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 . )
Recent meta-analyses reinforce the finding that 10 - 20 μg per day of vitamin D can reduce all-cause mortality and cancer mortality in middle-aged and older people .
Although vitamin D doses were greater than those assessed in the past , we found no new evidence that supplementation could have an effect on most non-skeletal conditions , including cardiovascular disease , adiposity , glucose metabolism , mood disorders , muscular function , tuberculosis , and colorectal adenomas , or on maternal and perinatal conditions .
The compilation of results from 83 trials showed that vitamin D supplementation had no significant effect on biomarkers of systemic inflammation .
The main new finding highlighted by this systematic review is that vitamin D supplementation might help to prevent common upper respiratory tract infections and asthma exacerbations .
There remains little evidence to suggest that vitamin D supplementation has an effect on most conditions , including chronic inflammation , despite use of increased doses of vitamin D , strengthening the hypothesis that low vitamin D status is a consequence of ill health , rather than its cause .
We further hypothesise that vitamin D supplementation could exert immunomodulatory effects that strengthen resistance to acute infections , which would reduce the risk of death in debilitated individuals .