Longitudinal association of vitamin B-6, folate, and vitamin B-12 with depressive symptoms among older adults over time.

BACKGROUND

B-vitamin deficiencies have been associated with depression; however, there is very little prospective evidence from population-based studies of older adults.

OBJECTIVE

We examined whether dietary intakes of vitamins B-6, folate, or vitamin B-12 were predictive of depressive symptoms over an average of 7.2 y in a community-based population of older adults.

DESIGN

The study sample consisted of 3503 adults from the Chicago Health and Aging project, an ongoing, population-based, biracial (59% African American) study in adults aged > or =65 y. Dietary assessment was made by food-frequency questionnaire. Incident depression was measured by the presence of > or =4 depressive symptoms from the 10-item version of the Center for Epidemiologic Studies Depression scale.

RESULTS

The logistic regression models, which used generalized estimating equations, showed that higher total intakes, which included supplementation, of vitamins B-6 and B-12 were associated with a decreased likelihood of incident depression for up to 12 y of follow-up, after adjustment for age, sex, race, education, income, and antidepressant medication use. For example, each 10 additional milligrams of vitamin B-6 and 10 additional micrograms of vitamin B-12 were associated with 2% lower odds of depressive symptoms per year. There was no association between depressive symptoms and food intakes of these vitamins or folate. These associations remained after adjustment for smoking, alcohol use, widowhood, caregiving status, cognitive function, physical disability, and medical conditions.

CONCLUSION

Our results support the hypotheses that high total intakes of vitamins B-6 and B-12 are protective of depressive symptoms over time in community-residing older adults.