Relationship of 25-hydroxyvitamin D with all-cause and cardiovascular disease mortality in older community-dwelling adults

BACKGROUND/OBJECTIVES: Vitamin D deficiency is associated with cardiovascular disease, osteoporosis, poor muscle strength, falls, fractures, and mortality. Although older adults are at a high risk of vitamin D deficiency, the relationship of serum 25(OH)D with all-cause and cardiovascular disease mortality has not been well characterized in the elderly. We hypothesized that low serum 25(OH)D predicted mortality in older adults. SUBJECTS/METHODS: Serum 25(OH)D and all-cause and cardiovascular disease mortality were examined in 1006 adults, ≥65 years, who participated in the InCHIANTI study, a population-based, prospective cohort study of aging in Tuscany, Italy. Serum 25(OH)D was measured at enrollment in 1998-1999, and participants were followed for mortality. RESULTS: During 6.5 years of follow-up, 228 (22.7%) participants died, of whom 107 died from cardiovascular disease. Compared with participants in the highest quartile of serum 25(OH)D (>26.5 ng/mL)(to convert to nmol/L, multiply by 2.496), those in the lowest quartile (<10.5 ng/mL) had increased risk of all-cause mortality (Hazards Ratio [H.R.] 2.11, 95% Confidence Interval [C.I.] 1.22 – 3.64, P = 0.007) and cardiovascular disease mortality (H.R. 2.64, 95% C.I. 1.14 – 4.79, P = 0.02), in multivariate Cox proportional hazards models that adjusted for age, sex, education, season, physical activity, and other potential confounders. CONCLUSIONS: Older community-dwelling adults with low serum 25(OH)D are at higher risk of all-cause and cardiovascular disease mortality.