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 .
A randomized controlled trial of vitamin D3 supplementation in African American women.
BACKGROUND We conducted a r and omized , placebo-controlled , double-blind trial to test the hypothesis that vitamin D(3 ) supplementation would prevent bone loss in calcium-replete , African American postmenopausal women . METHODS Two hundred eight healthy black postmenopausal women , 50 to 75 years of age , were assigned to receive either placebo or 20 microg/d ( 800 IU ) of vitamin D(3 ) . Calcium supplements were provided to ensure a total calcium intake of 1200 to 1500 mg/d . After 2 years , the vitamin D(3 ) dose was increased to 50 microg/d ( 2000 IU ) in the active group , and the study continued for an additional year . Bone mineral density ( BMD ) was measured every 6 months . Markers of bone turnover , vitamin D metabolites , and parathyroid hormone ( PTH ) levels were measured in serum . RESULTS There were no significant differences in BMD between the active and control groups throughout the study . There was also no relationship between serum 25-hydroxyvitamin D levels attained and rates of bone loss . There was an increase in BMD of the total body , hip , and radius at 1 year in both groups . Over the 3 years , BMD declined at these sites by 0.26 % to 0.55 % per year . The BMD of the lumbar spine increased slightly in the placebo and active groups . There were no persistent changes in serum PTH levels or the markers of bone turnover , although there was a transient decline in PTH in both groups at 3 months . No significant adverse events were attributed to vitamin D supplementation . CONCLUSIONS There was no observed effect of vitamin D(3 ) supplementation on bone loss or bone turnover markers in calcium-replete , postmenopausal African American women . Further studies are needed to determine if these findings are applicable to women of other ethnic groups
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 .