Abstract 3641: 25-OH Vitamin D Deficiency and the Risk of All-Cause Mortality in the General Population: Results from the Third National Health and Nutrition Examination Survey Linked Mortality Data
Background: Vitamin D deficiency is common. In patients on dialysis, activated vitamin D therapy is associated with reduced mortality. However, whether low 25-hydroxyvitamin D (25-OH D) levels are associated with mortality in the general population is unknown.
Methods: Using multivariable Poisson regression, we tested the association of low 25-OH D levels with all-cause, cardiovascular disease (CVD), and cancer mortality in 12,534 adults >20 years old with preserved renal function (eGFR>60 ml/min/1.73 m2) from the Third National Health and Nutrition Examination Survey (NHANES III) Linked Mortality Files.
Results: Increasing age, female sex, non-white race/ethnicity, diabetes, current smoking, and increasing BMI were all independently associated with increased odds of 25-OH D deficiency (lowest quartile), while increasing physical activity, use of vitamin D supplements, and non-winter season were inversely associated. During a median 8.7 years of follow-up, there were 1380 deaths including 551 from CVD and 356 from cancer. In multivariable models (adjusted for baseline demographics, CVD risk factors, season, vitamin D supplementation and physical activity), compared to the highest quartile, 25-OH D levels <17.8 ng/ml were associated with a 22% increased rate of all-cause mortality [IRR 1.22 (95% CI 1.03–1.46)] and a population attributable risk of 3.1%. There was also a trend for increased rate of CVD mortality in the lowest 25-OH D quartile [1.22 (0.84 –1.79)]. The lowest quartile of 25-OH D was not associated with cancer-specific mortality in unadjusted [1.12 (0.78 –1.59)] or limited adjusted models [1.11 (0.77–1.59)]. Results were similar for models including all participants with eGFR values above 15 ml/min/1.73m2.
Conclusion: Vitamin D deficiency (<17.8 ng/ml) is independently associated with all-cause mortality in the general population. Further observational studies and randomized clinical trials are needed to confirm these findings.