Research Article Low 25-Hydroxyvitamin D Concentrations Predict Incident Depression in Well-Functioning Older Adults: The Health, Aging, and Body Composition Study

Background. Cross-sectional studies suggest that low 25-hydroxyvitamin D (25[OH]D) may be a risk factor for depression; however, there are few prospective studies. We examined the association between 25(OH)D and depressive symptoms in community-dwelling persons aged 70–79 years in the Health, Aging, and Body Composition (Health ABC) Study (n = 2598). Methods. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression Scale (CES-D) at baseline and 2-, 3- and 4-year follow-up. Serum 25(OH)D was measured at 1-year follow-up and categorized as <20, 20–<30, and ≥30 ng/mL. Mixed models were used to examine change in CES-D scores according to 25(OH)D categories. The association between 25(OH)D categories and incident depression (CES-D short score ≥10 or antidepressant medication use) were assessed using Cox proportional hazards models