['Recent studies suggest that vitamin D metabolites may be important for preserving cognitive function via specific neuroprotective effects. No large studies have examined the association between vitamin D status and cognition.', "In this cross-sectional study, we analyzed the serum 25-hydroxyvitamin D(3) levels and Mini-Mental State Examination (MMSE) test scores of 225 older outpatients who were diagnosed as having probable Alzheimer's disease (AD). In addition to the 25-hydroxyvitamin D(3) levels, we analyzed the serum vitamin B(1), B(6) and B(12) levels.", 'An association was found between MMSE test scores and serum 25-hydroxyvitamin D(3) levels, with a beta-coefficient of 0.05 (p = 0.01). Vitamin-D-sufficient patients had significantly higher MMSE scores as compared to vitamin-D-insufficient ones. No association was found with the other serum vitamin levels.'] Are higher serum vitamin D3 levels associated with better cognitive test performance in patients with Alzheimer 's disease?