Vitamin D Status and Rates of Cognitive Decline in a Multi ethnic Cohort of Older Adults

Objective: To assess associations between Vit D status and trajectories of change in sub domains of cognitive function in a cohort of ethnically diverse older adults

Design, Setting, and Participants: Longitudinal multi ethnic cohort study of 382 participants in an outpatient clinic enrolled between February 2002 and August 2010 with baseline assessment and yearly follow-up visits. Serum 25-hydroxy vitamin D (25-OHD)was measured, with Vit D status defined as the following: deficient, less than 12ng/mL(to convert to nanomoles per litre, multiply by 2.496); insufficient, 12 to less than 20ng/mL; adequate, 20 to less than 50ng/mL; or high, 50ng/mL or higher. Sub domains of cognitive function were assessed using the Spanish and English Neuropsychological Assessment Scales. Associations were evaluated between 25-OHD levels (as continuous and categorical [deficient, insufficient, or adequate]) and trajectories of cognitive decline.