Low 25-hydroxyvitamin D is associated with increased mortality in female nursing home residents.

CONTEXT Vitamin D deficiency contributes to skeletal diseases and is highly prevalent among institutionalized elderly patients. Whether low 25-hydroxyvitamin D (25[OH]D) concentrations are an independent risk factor for mortality in these patients is, however, unclear. OBJECTIVE We aimed to evaluate whether 25(OH)D concentrations are associated with mortality. DESIGN, SETTING, AND PARTICIPANTS This is a prospective cohort study among elderly female patients (age >70 yr) recruited from 95 nursing homes in Austria. MAIN OUTCOME MEASURES We calculated Cox proportional hazard ratios (HR) for all-cause mortality according to 25(OH)D quartiles. RESULTS We examined 961 study participants (age 83.7 ± 6.1 yr). Median 25(OH)D concentration was 17.5 (interquartile range 13.7-25.5) nmol/liter, and 93% of our cohort had 25(OH)D levels below 50 nmol/liter. During a mean follow-up time of 27 ± 8 months, 284 patients died. Compared with the fourth quartile (25[OH]D >25.5 nmol/liter), the age-adjusted HR (with 95% confidence interval) was 1.49 (1.07-2.10) in the first 25(OH)D quartile (25[OH]D <14.0 nmol/liter), and this association remained significant after multivariate adjustments (HR = 1.56; 95% confidence interval = 1.01-2.40). CONCLUSIONS This Austrian study suggests that the majority of institutionalized female patients are vitamin D deficient during winter and that there was an inverse association of 25(OH)D and mortality. These data underscore the urgent need for effective strategies for the prevention and treatment of vitamin D deficiency, in particular in the setting of nursing homes.