Vitamin B1 (Thiamine) for Cognitive Function

Research suggests a possible association between vitamin B1 levels and cognitive function, though the evidence base here is quite limited. The available supporting study — a cross-sectional observational analysis of memory clinic patients in Japan — found that women with lower blood levels of vitamin B1 had higher odds of dementia compared to those with higher levels, while no such pattern was observed in men. Importantly, cross-sectional designs cannot establish whether low vitamin B1 levels precede cognitive decline or result from it, and the second linked study concerns COVID-19 drug screening and does not speak to thiamine or cognition at all, leaving the relevant evidence pool effectively consisting of a single observational study. Overall, the current research is insufficient to draw firm conclusions about vitamin B1 and cognitive function, and further longitudinal and controlled studies are needed to clarify any meaningful relationship.