Among vitamin B12 deficient older people, high folate levels are associated with worse cognitive function: combined data from three cohorts.

Background: Folate fortification of food aims to reduce the number of babies born with neural tube defects, but has been associated with cognitive impairment when vitamin B12 levels are deficient. Given the prevalence of low vitamin B12 levels among the elderly, and the global deployment of food fortification programs, investigation of the associations between cognitive impairment, vitamin B12, and folate are needed.

Objective: To investigate the associations of serum vitamin B12, red cell folate, and cognitive impairment.

Increased risk of cognitive impairment in patients with diabetes is associated with metformin.

Objective: To investigate the associations of metformin, serum vitamin B12, calcium supplements, and cognitive impairment in patients with diabetes.

Research Design And Methods: Participants were recruited from the Primary Research in Memory (PRIME) clinics study, the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging, and the Barwon region of southeastern Australia. Patients with Alzheimer disease (AD) (n=480) or mild cognitive impairment (n=187) and those who were cognitively intact (n=687) were included; patients with stroke or with neurodegenerative diseases other than AD were excluded.