Vitamin D Deficiency Is Associated With an Increased Likelihood of Incident Depression in Community-Dwelling Older Adults.
Level 3 - non-randomized controlled study
Prospective cohort study with longitudinal follow-up
PubMed 30470577 · doi:10.1016/j.jamda.2018.10.006
What was done
This prospective longitudinal cohort study examined the relationship between baseline vitamin D levels and incident depression at 2 and 4 years (waves 2 and 3) within the Irish Longitudinal Study on Aging (TILDA). The study included 3,965 community-dwelling adults aged 50 years and older who were free of depression at baseline. Vitamin D concentrations were measured using liquid chromatography-tandem mass spectrometry and classified as deficient (<30 nmol/L), insufficient (30-50 nmol/L), or sufficient (>50 nmol/L). Incident depression was defined as a Center for Epidemiologic Studies Depression Scale-8 (CES-D-8) score ≥9 at wave 2 or wave 3. Logistic regression models, weighted for attrition and adjusted for physical activity, chronic disease burden, cardiovascular disease, and antidepressant use, were used to evaluate odds ratios.
What was found
Incident depression occurred in 400 out of 3,965 participants. The incident depression group had a higher likelihood of baseline vitamin D deficiency (proportional estimation 19.4%, 95% CI 15.1-24.7) compared to the non-incident group (12.4%, 95% CI 11.1-14.0; Z = 3.93, P < .001). In adjusted logistic regression models, participants with baseline vitamin D deficiency had a significantly increased likelihood of incident depression (OR 1.75, 95% CI 1.24-2.46; t = 3.21; P = .001).
Why it matters
This study provides longitudinal evidence linking vitamin D deficiency to a higher risk of developing late-life depression. Given the high prevalence of deficiency and low risk of supplementation, vitamin D status represents a potentially modifiable factor for late-life mental health.
Limits
The observational design precludes establishing causality and cannot rule out residual confounding. Depression was assessed via a self-reported screening tool (CES-D-8) rather than structured clinical diagnostic interviews. Vitamin D was measured only at baseline, so subsequent changes or supplementation were not accounted for.
Cited by
- context The Irish Longitudinal Study on Ageing (TILDA) showed that vitamin D supplementation provided health benefits.