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 .
1,25-Dihydroxyvitamin D3 and muscle strength in the elderly: a randomized controlled trial.
An unexplained loss of muscle strength occurs with aging . Vitamin D deficiency can cause myopathy and administration of 1,25-dihydroxyvitamin D3 [ 1,25-(OH2)D3 ] to persons with low serum concentrations can improve strength . To test the hypothesis that the weakness associated with aging is in part due to inadequate serum concentrations of [ 1,25-(OH2)D3 ] , we conducted a r and omized , controlled , double blinded trial in 98 men and women volunteers over 69 yr old . Treatment consisted of 0.25 micrograms 1,25-(OH)2D3 , orally , twice per day or identical placebo for 6 months .  Leg muscle strength of the quadriceps was measured with an isokinetic dynamometer . There was no difference between the two groups at 1 week , 1 month , or 6 months of treatment in any of the measures of muscle strength . We conclude that oral administration of 0.5 micrograms 1,25-(OH)2D3/day does not improve muscle strength in older persons . Further research is needed to determine the etiology of the decline in muscle strength associated with aging
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 .