In subgroup analyses , all cause mortality was significantly lower in trials with vitamin D3 supplementation than in trials with vitamin D2 supplementation ( P for interaction=0.04 ) ; neither vitamin D3 nor vitamin D2 was associated with a statistically significant reduction in all cause mortality .
CONCLUSIONS Vitamin D supplementation alone was not associated with  all cause mortality in adults compared with placebo or no treatment .
Vitamin D supplementation reduced the risk of cancer death by 16 % .
Additional large clinical studies are needed to determine whether vitamin D3 supplementation is associated with lower all cause mortality .
OBJECTIVE To investigate whether vitamin D supplementation is associated with lower mortality in adults .
Effect of monthly high‐dose vitamin D on bone density in community‐dwelling older adults substudy of a randomized controlled trial
BACKGROUND Severe vitamin D deficiency causes osteomalacia , yet trials of vitamin D supplementation in the community have not on average demonstrated benefit to bone mineral density ( BMD ) or fracture risk in adults . OBJECTIVE To determine whether monthly high-dose vitamin D supplementation influences BMD in the general population and in those with low 25-hydroxyvitamin D levels . METHODS Two-year sub study of a trial in older community-resident adults . A total of 452 participants were r and omized to receive monthly doses of vitamin D3 100 000 IU , or placebo . The primary end-point was change in lumbar spine BMD . Exploratory analyses to identify thresholds of baseline 25-hydroxyvitamin D for vitamin D effects on BMD were prespecified . RESULTS Intention-to-treat analyses showed no significant treatment effect in the lumbar spine ( between-groups difference 0.0071 g cm-2 , 95%CI : -0.0012 , 0.0154 ) or total body but BMD loss at both hip sites was significantly attenuated by ~1/2 % over 2 years . There was a significant interaction between baseline 25-hydroxyvitamin D and treatment effect ( P = 0.04 ) . With baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 ( n = 46 ) , there were between-groups BMD changes at the spine and femoral sites of ~2 % , significant in the spine and femoral neck , but there was no effect on total body BMD . When baseline 25-hydroxyvitamin D was > 30 nmol L-1 , differences were ~1/2 % and significant only at the total hip . CONCLUSIONS This sub study finds no clinical ly important benefit to BMD  from untargeted vitamin D supplementation of older , community-dwelling adults . Exploratory analyses suggest meaningful benefit in those with baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 . This represents a significant step towards a trial-based definition of vitamin D deficiency for bone health in older adults
In subgroup analyses , all cause mortality was significantly lower in trials with vitamin D3 supplementation than in trials with vitamin D2 supplementation ( P for interaction=0.04 ) ; neither vitamin D3 nor vitamin D2 was associated with a statistically significant reduction in all cause mortality .
CONCLUSIONS Vitamin D supplementation alone was not associated with  all cause mortality in adults compared with placebo or no treatment .
Vitamin D supplementation reduced the risk of cancer death by 16 % .
Additional large clinical studies are needed to determine whether vitamin D3 supplementation is associated with lower all cause mortality .
OBJECTIVE To investigate whether vitamin D supplementation is associated with lower mortality in adults .