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. Analyses were adjusted for socio-demographic and behavioral characteristics, season, and chronic conditions. Results. Thirty-three percent of participants had 25(OH)D <20 ng/mL. Serum 25(OH)D was not associated with CES-D scores at baseline (p = .51); however, CES-D scores increased over time and were significantly associated with 25(OH)D at 2-year (p = .003) and 4-year follow-up (p < .001). Among 2,156 participants free of depression at the 1-year follow-up, the cumulative incidence of depression was 26.9%. Participants with 25(OH)D <20 ng/mL were at greater risk of developing depression (HR [95% CI]: 1.65 [1.23.2.22]) over 4 years of follow-up compared with those with 25(OH)D .30 ng/mL. Conclusion. Low 25(OH)D was independently associated with a greater increase in depressive symptom scores and incident depression in community-dwelling older adults.