Low 25-Hydroxyvitamin D [25(OH)D] Levels as a Predictor of Depressive Symptoms: Evidence from Community-Dwelling Older Adults Population in Mexico City.

Objective: The purpose of this study was to assess the association between serum 25-hydroxyvitamin D [25(OH)D] levels and depressive symptoms in Mexican older adults 70 years and older.

Methods: A total of 326 adults aged 70 or older from Coyoacán Cohort Study were included in this study. The depressive symptoms were assessing by Center for Epidemiologic Studies Depression Scale (CES-D) and serum 25-hydroxyvitamin D [25(OH)D] levels were measured by commercially available enzyme-linked immunosorbent assay (ELISA).

Results: Overall, the prevalence of depressive symptoms was 36.5%. The mean age was 79 years, and 53.4% were women. The total serum 25-hydroxyvitamin D [25(OH)D] levels were lower in older adults with depressive symptoms when compared with older adults without depressive symptoms (p = .006). Logistic regression models showed a significant association between low serum 25(OH)D levels and depressive symptoms even after adjusting for potential confounders (OR = 2.453; 95% CI:1.218-4.939; p = .012). In addition, linear regression model to predict the effect of 25-hydroxyvitamin D [25(OH)D] levels on the CES-D score as a continuous variable, was statistically significant [F_(1,324) = 8.54, p = .004], and the R-squared value was .026, indicating that this regression model explains 2.6% of the change in the CES-D score.

Conclusion: These results suggest that older Mexican adults with lower serum 25-hydroxyvitamin D [25(OH)D] levels are at higher risk of presenting depressive symptoms.