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 .
Independent association of low serum 25-hydroxyvitamin d and 1,25-dihydroxyvitamin d levels with all-cause and cardiovascular mortality.
BACKGROUND In cross-sectional studies , low serum levels of 25-hydroxyvitamin D are associated with higher prevalence of cardiovascular risk factors and disease . This study aim ed to determine whether endogenous 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels are related to all-cause and cardiovascular mortality . METHODS Prospect i ve cohort study of 3258 consecutive male and female patients ( mean [ SD ] age , 62 [ 10 ] years ) scheduled for coronary angiography at a single tertiary center . We formed quartiles according to 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels within each month of blood drawings . The main outcome measures were all-cause and cardiovascular deaths . RESULTS During a median follow-up period of 7.7 years , 737 patients ( 22.6 % ) died , including 463 deaths from cardiovascular causes . Multivariate-adjusted hazard ratios ( HRs ) for patients in the lower two 25-hydroxyvitamin D quartiles ( median , 7.6 and 13.3 ng/mL [ to convert 25-hydroxyvitamin D levels to nanomoles per liter , multiply by 2.496 ] ) were higher for all-cause mortality ( HR , 2.08 ; 95 % confidence interval [ CI ] , 1.60 - 2.70 ; and HR , 1.53 ; 95 % CI , 1.17 - 2.01 ; respectively ) and for cardiovascular mortality ( HR , 2.22 ; 95 % CI , 1.57 - 3.13 ; and HR , 1.82 ; 95 % CI , 1.29 - 2.58 ; respectively ) compared with patients in the highest 25-hydroxyvitamin D quartile ( median , 28.4 ng/mL ) . Similar results were obtained for patients in the lowest 1,25-dihydroxyvitamin D quartile . These effects were independent of coronary artery disease , physical activity level , Charlson Comorbidity Index , variables of mineral metabolism , and New York Heart Association functional class . Low 25-hydroxyvitamin D levels were significantly correlated with variables of inflammation ( C-reactive protein and interleukin 6 levels ) , oxidative burden ( serum phospholipid and glutathione levels ) , and cell adhesion ( vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 levels ) . CONCLUSIONS Low 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels are independently associated with all-cause and cardiovascular mortality . A causal relationship has yet to be proved by intervention trials using vitamin
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 .