Associations of vitamin B12 status with cognitive domain performance in cognitively healthy older adults

Background Increasing longevity worldwide has resulted in an unprecedented high burden of dementia. Several lines of research have implicated factors affecting B‐vitamin status among risk factors for cognitive decline and dementia. We aimed to determine the prevalence of vitamin B12 deficiency among cognitively healthy volunteers from the Cognitive Health in Ageing Register: Investigational, Observational, and Trial Studies in Dementia Research: Prospective Readiness cOhort (CHARIOT:PRO) SubStudy (CPRO‐SS) and also, to explore associations with cognitive performance at screening. Method This analysis includes data from cognitively healthy volunteers (n=1946) aged 60‐85 years who underwent, as part of screening, Repeatable Battery for Neuropsychological Status (RBANS), vitamin B12 and folate measures. Levels of B12 biomarkers, homocysteine and methylmalonic acid, were assayed for those with low vitamin B12 (