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 .
Biochemical parameters after cholecalciferol repletion in hemodialysis: results From the VitaDial randomized trial.
BACKGROUND The 2009 KDIGO ( Kidney Disease : Improving Global Outcomes ) chronic kidney disease-mineral and bone disorder clinical practice guideline suggests correcting 25-hydroxyvitamin D3 ( 25[OH]D ) levels<30ng/mL in patients treated with maintenance hemodialysis  , but does not provide a specific treatment protocol . STUDY DESIGN 2-center , double-blind , r and omized , 13-week , controlled trial followed by a 26-week open-label study . SETTING & PARTICIPANTS 55 adult maintenance hemodialysis patients with 25(OH)D levels<30ng/mL were recruited from June 2008 through October 2009 . INTERVENTION Cholecalciferol , 25,000IU , per week orally versus placebo for 13 weeks , then 26 weeks of individualized cholecalciferol prescription based on NKF-KDOQI ( National Kidney Foundation-Kidney Disease Outcomes Quality Initiative ) guidelines . OUTCOMES Primary end point was the percentage of patients with 25(OH)D levels≥30ng/mL at 13 weeks . Secondary outcomes included the percentage of patients with normal calcium , phosphorus , and intact parathyroid hormone ( iPTH ) blood levels . Safety measures included incidence of hypercalcemia and hypervitaminosis D. MEASUREMENTS Blood calcium and phosphate were measured weekly ; iPTH , 25(OH)D , 1,25-dihydroxyvitamin D3 ( 1,25[OH]2D ) , and bone turnover markers , trimonthly ; fetuin A and fibroblast growth factor 23 ( FGF-23 ) serum levels and aortic calcification scores were determined at weeks 0 and 39 . RESULTS The primary end point significantly increased in the treatment group compared with the placebo group ( 61.5 % vs 7.4 % ; P<0.001 ) , as well as 1,25(OH)2D levels ( 22.5 [ IQR , 15 - 26 ] vs 11 [ IQR , 10 - 15]pg/mL ; P<0.001 ) and the proportion of patients achieving the target calcium level ( 76.9 % vs 48.2 % ; P=0.03 ) . Incidence of hypercalcemia and phosphate and iPTH levels were similar between groups . The second 26-week study phase did not significantly modify the prevalence of 25(OH)D level≥30ng/mL in patients issued from the placebo group . LIMITATIONS Small size of the study population . CONCLUSIONS Oral weekly administration of 25,000IU of cholecalciferol for 13 weeks is an effective , safe , inexpensive , and manageable way to increase 25(OH)D and 1,25(OH)2D levels in hemodialysis patients . Further evaluation of clinical end points is suggested
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 .