Serum 25-Hydroxyvitamin D Levels and All-Cause or Cardiovascular Disease Mortality among US adults with Hypertension

Background: Research suggests that serum concentrations of 25-hydroxyvitamin D (25[OH]D) are inversely associated with hypertension incidence, but it remains unknown whether concentrations of 25(OH)D are inversely associated with mortality among hypertensive adults. This study examined the relationship between concentrations of 25(OH)D and risk of death among US adults with hypertension using a nationally representative sample. Method: We analyzed data from the 2001-2004 National Health and Nutrition Examination Survey with mortality data (matched to the National Death Index) followed up through 2006. We estimated the Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs) for death from all causes and cardiovascular disease (CVD) associated with 25(OH)D. Results: Of 2,617 hypertensive adults, 192 died during the mean 4-year follow-up with 68 deaths from CVD. Compared with participants with 25(OH)D concentrations in the highest quartile (≥29 ng/mL), the HRs for death from all causes were 1.90 (95% CI: 1.03-3.48), 1.31 (95% CI: 0.84-2.03), and 1.36 (95% CI: 0.83-2.22), respectively, and the HRs for death from CVD were 3.11 (95% CI: 1.11-8.67), 2.44 (95% CI: 0.85-7.00), and 2.34 (95% CI: 0.89-6.15), respectively, in the first (<17 ng/mL), second (17-<23 ng/mL) and third (23-<29 ng/mL) quartiles of 25(OH)D after adjustment for potential confounding variables. There were significantly linear inverse trends between concentrations of 25(OH)D and the risk of death from all causes (P=0.013) and CVD (P=0.010). Conclusions: Concentrations of 25(OH)D were inversely associated with all-cause and CVD mortality in hypertensive adults of the United States. Enhancing vitamin D nutrition may provide a means of preventing premature death.