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 .
Prediagnostic 25-Hydroxyvitamin D, VDR and CASR Polymorphisms, and Survival in Patients with Colorectal Cancer in Western European Populations
Background : Individuals with higher blood 25-hydroxyvitamin D [ 25(OH)D ] levels have a lower risk of developing colorectal cancer ( CRC ) , but the influence of 25(OH)D on mortality after CRC diagnosis is unknown . Methods : The association between prediagnostic 25(OH)D levels and CRC-specific ( N = 444 ) and overall mortality ( N = 541 ) was prospect ively examined among 1,202 participants diagnosed with CRC between 1992 and 2003 in the European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) cohort . Multivariable Cox proportional hazards models were used to calculate HRs and corresponding 95 % CIs according to 25(OH)D quintiles and genetic variation within the VDR and CASR genes . Potential dietary , lifestyle , and metabolic effect modifiers were also investigated . Results : There were 541 deaths , 444 ( 82 % ) due to CRC . Mean follow-up was 73 months . In multivariable analysis , higher 25(OH)D levels were associated with a statistically significant reduction in CRC-specific ( Ptrend = 0.04 ) and overall mortality ( Ptrend = 0.01 ) . Participants with 25(OH)D levels in the highest quintile had an adjusted HR of 0.69 ( 95 % CI : 0.50–0.93 ) for CRC-specific mortality and 0.67 ( 95 % CI : 0.50–0.88 ) for overall mortality , compared with the lowest quintile . Except for a possible interaction by prediagnostic dietary calcium intake ( Pinteraction = 0.01 ) , no other potential modifying factors related to CRC survival were noted . The VDR ( FokI and BsmI ) and CASR ( rs1801725 ) genotypes were not associated with survival . Conclusions : High prediagnostic 25(OH)D levels are associated with improved survival of patients with CRC . Impact : Our findings may stimulate further research directed at investigating the effects of blood vitamin D levels before , at , and after CRC diagnosis on outcomes in CRC patients . Cancer Epidemiol Biomarkers Prev ; 21(4 ) ; 582–93 . © 2012 AACR
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 .