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 .
Low levels of vitamin D are associated with increased mortality in patients attending a university hospital in Denmark
Abstract Introduction . Increased mortality in patients with low serum concentrations of S-25(OH)D  has been described , though no causal relationship has been shown . The aim of this cohort study was to investigate the possible association between S-25(OH)D status and  all-cause mortality in 5,147 patients attending a university hospital in Denmark from 2003–2008 . Methods . Serum was analyzed for ionized calcium ( S-Ca2 + ) , parathyroid hormone ( S-PTH ) and S-25(OH)D. Kaplan-Meier curves were used to analyze the association between S-25(OH)D quartiles , S-PTH-quartiles and all-cause mortality . Cox regression analyzed associations of age , gender , concentrations of ionized calcium , S-PTH and S-25(OH)D with all-cause mortality . Results . Log rank tests for both S-25(OH)D and S-PTH quartiles showed a significant difference across the quartiles . The Cox regression analysis showed a hazard ratio ( HR ) for death of 1.02 ( 95 % CI : 1.01 ; 1.03 ) for S-PTH per pmol/L increase , 1.07 ( 95 % CI : 1.05 ; 1.10 ) for S-25(OH)D per 10 nmol/L decrease and 0.54 ( 95 % CI : 0.24 ; 1.20 ) for S-Ca2 + per mmol/L increase . Discussion . This study supports growing evidence , that low serum concentrations of 25(OH)D are associated with an increased all-cause mortality ; however the nature of the study prevents the finding of a causal relationship . In the Cox regression analysis S-25(OH)D concentrations in the blood were inversely associated with all-cause mortality . Prospect i ve controlled studies are needed to confirm a causal relationship between low S-25(OH)D concentrations and mortality
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 .