Vitamins B6, B12 May Protect Against Depression in Older Adults

Laurie Barclay, MD

July 01, 2010

July 1, 2010 — High total intakes of vitamins B6 and B12 are associated with a lower risk for depressive symptoms over time in community-residing older adults, according to the results of a cohort study reported online June 2 in the American Journal of Clinical Nutrition.

"B-vitamin deficiencies have been associated with depression; however, there is very little prospective evidence from population-based studies of older adults," write Kimberly A. Skarupski, from Rush University Medical Center in Chicago, Illinois, and colleagues. "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."

The Chicago Health and Aging project is an ongoing, population-based study in adults at least 65 years old. A sample of 3503 adults from this cohort, of whom 59% were African American, completed a food frequency questionnaire for dietary assessment. The 10-item version of the Center for Epidemiologic Studies Depression scale was used to determine incident depression, defined as 4 or more depressive symptoms. The association between vitamin intake and depression was examined with logistic regression models using generalized estimating equations.

After adjustment for age, sex, race, education, income, and use of antidepressant medications, higher total vitamin intakes including supplements were associated with a lower risk for incident depression during follow-up for up to 12 years. Odds of depressive symptoms were 2% lower per year for each additional 10 mg of vitamin B6 and an additional 10 μg of vitamin B12. Further adjustment for smoking, alcohol intake, widowhood, caregiver status, cognitive function, physical disability, and medical conditions did not abolish these associations. Food intakes of these vitamins or folate were not associated with depressive symptoms.

"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," the study authors write.

Limitations of this study include observational design with possible confounding, inability to infer causality, reliance on self-reported data, and lack of generalizability to other race-ethnic subpopulations of older adults.

"In the assessment and treatment of depressive symptoms in older adults, clinicians and other healthcare professionals should be mindful of the patient's nutritional status in general, and whether there are vitamin insufficiencies in these nutrients before treatment," the study authors conclude.

The National Institutes of Health/National Institutes of Aging supported this study. The study authors have disclosed no relevant financial relationships.

Am J Clin Nutr. Published online June 2, 2010.