Subgroup analyses in the observational studies indicated that risk of mortality was significantly higher in studies with lower baseline use of vitamin D supplements .
The effects observed for vitamin D3 supplementation remained unchanged when grouped by various characteristics .
However , for vitamin D2 supplementation , increased risks of mortality were observed in studies with lower intervention doses and shorter average intervention periods .
Conclusions Evidence from observational studies indicates inverse associations of circulating 25-hydroxyvitamin D with risks of death due to cardiovascular disease , cancer , and other causes .
Objective To evaluate the extent to which circulating biomarker and supplements of vitamin D are associated with  mortality from cardiovascular , cancer , or other conditions  , under various circumstances .
Circulating calcitriol concentrations and total mortality.
BACKGROUND Evidence is accumulating that vitamin D supplementation of patients with low 25-hydroxyvitamin D concentrations is associated with lower cardiovascular morbidity and total mortality during long-term follow-up . Little is known , however , about the effect of low concentrations of the vitamin D hormone calcitriol on total mortality . We therefore evaluated the predictive value of circulating calcitriol for midterm mortality in patients of a specialized heart center . METHODS This prospect i ve cohort study included 510 patients , 67.7 % with heart failure ( two-thirds in end stage ) , 64.3 % hypertension , 33.7 % coronary heart disease , 20.2 % diabetes , and 17.3 % renal failure . We followed the patients for up to 1 year after blood collection . For data analysis , the study cohort was stratified into quintiles of circulating calcitriol concentrations . RESULTS Patients in the lowest calcitriol quintile were more likely to have coronary heart disease , heart failure , hypertension , diabetes , and renal failure compared to other patients . They also had low 25-hydroxyvitamin D concentrations and high concentrations of creatinine , C-reactive protein , and tumor necrosis factor alpha . Eighty-two patients ( 16.0 % ) died during follow-up . Probability of 1-year survival was 66.7 % in the lowest calcitriol quintile , 82.2 % in the second quintile , 86.7 % in the intermediate quintile , 88.8 % in the fourth quintile , and 96.1 % in the highest quintile ( P < 0.001 ) . Discrimination between survivors and nonsurvivors was best when a cutoff value of 25 ng/L was applied ( area under the ROC curve 0.72 ; 95 % CI 0.66 - 0.78 ) . CONCLUSIONS Decreased calcitriol levels are linked to excess midterm mortality in patients of a specialized heart center
Subgroup analyses in the observational studies indicated that risk of mortality was significantly higher in studies with lower baseline use of vitamin D supplements .
The effects observed for vitamin D3 supplementation remained unchanged when grouped by various characteristics .
However , for vitamin D2 supplementation , increased risks of mortality were observed in studies with lower intervention doses and shorter average intervention periods .
Conclusions Evidence from observational studies indicates inverse associations of circulating 25-hydroxyvitamin D with risks of death due to cardiovascular disease , cancer , and other causes .
Objective To evaluate the extent to which circulating biomarker and supplements of vitamin D are associated with  mortality from cardiovascular , cancer , or other conditions  , under various circumstances .