Association of Serum 25-Hydroxyvitamin D Concentrations With All-Cause and Cause-Specific Mortality Among Individuals With Diabetes

OBJECTIVE The evidence regarding vitamin D status and mortality among diabetes is scarce. This study aimed to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among adults with diabetes. RESEARCH DESIGN AND METHODS This study included 6,329 adults with diabetes from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001–2014. Death outcomes were ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% CIs for mortality from all causes, cardiovascular disease (CVD), and cancer. RESULTS The weighted mean (95% CI) level of serum 25(OH)D was 57.7 (56.6, 58.8) nmol/L, and 46.6% had deficient vitamin D ( 75 nmol/L were 0.59 (0.43, 0.83) for all-cause mortality (Ptrend = 0.003), 0.50 (0.29, 0.86) for CVD mortality (Ptrend = 0.02), and 0.49 (0.23, 1.04) for cancer mortality (Ptrend = 0.12). CONCLUSIONS Higher serum 25(OH)D levels were significantly associated with lower all-cause and CVD mortality. These findings suggest that maintaining adequate vitamin D status may lower mortality risk in individuals with diabetes.