Associations between dietary intake of folate and vitamins B-12 and B-6 and self-reported cognitive function and psychological well-being in Australian men and women in midlife.

OBJECTIVES: To assess dietary intake status of folate and vitamins B-12 and B-6 in 1183 middle-aged men and women, and to examine associations between dietary intake of these vitamins and self-reported cognitive function and psychological well-being.
METHODS: A population-based sample of urban and rural South Australians completed questionnaires assessing demographics, background, health, and self-reported cognitive and memory functioning and psychological well-being. Usual dietary intake status was estimated using a retrospective, self-report, quantified food frequency questionnaire.
RESULTS: About 20% of both men and women had intakes of folate that were below the Recommended Daily Intake for Australia. Vitamins B-12 and B-6 were positively related to memory functioning in men, and moderate dietary intake of folate and B-6 was associated with better memory functioning in women.
CONCLUSIONS: Vitamin B-12 and B-6 intakes may be positively related to the memory performance of middle-aged men and intakes at around the RDI are associated with better memory functioning for women. The investigation of the dose-response effects of B vitamin supplementation on cognition and mood in middle-aged men and women using objective measures of cognition and accounting for the influence of confounding factors such age and education would be informative.