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 .
Vitamin D Levels, Microvascular Complications, and Mortality in Type 1 Diabetes
OBJECTIVE To evaluate vitamin D as a predictor of all-cause mortality , progression from normoalbuminuria to micro- or macroalbuminuria , and the development of background or proliferative retinopathy in patients with type 1 diabetes . RESEARCH DESIGN AND METHODS A prospect i ve observational follow-up study in which an inception cohort of type 1 diabetic patients was followed from onset of diabetes diagnosed between 1979 and 1984 .  Plasma vitamin D [ 25(OH)D3 ] levels  were determined by high performance liquid chromatography/t and em mass spectrometry in 227 patients before the patients developed microalbuminuria . Values equal to or below the 10 % percentile ( 15.5 nmol/L ) were considered severe vitamin D deficiency . RESULTS Median ( range ) vitamin D  was 44.6 ( 1.7–161.7 ) nmol/L.  Vitamin D level was not associated with age , sex , urinary albumin excretion rate ( UAER ) , or blood pressure . During follow-up , 44 ( 18 % ) patients died . In a Cox proportional hazards model , the hazard ratio for mortality in subjects with severe vitamin D deficiency was 2.7 ( 1.1–6.7 ) , P = 0.03 , after adjustment for UAER , HbA1c , and conventional cardiovascular risk factors ( age , sex , blood pressure , cholesterol , smoking ) . Of the 220 patients , 81 ( 37 % ) developed microalbuminuria and 27 ( 12 % ) of these progressed to macroalbuminuria . Furthermore , 192 ( 87 % ) patients developed background retinopathy , whereas 34 ( 15 % ) progressed to proliferative retinopathy . Severe vitamin D deficiency at baseline did not predict the development of these microvascular complications . CONCLUSIONS In patients with type 1 diabetes , severe vitamin D deficiency independently predicts all-cause mortality but not development of microvascular complications in the eye and kidney . Whether vitamin D substitution in type 1 diabetic patients can improve the prognosis remains to be investigated
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 .