Association between vitamin B12 levels and cognitive impairment in older adults.

Abstract

Whether vitamin B12 deficiency is associated with cognitive impairment remains controversial. To determine the association between vitamin B12 serum levels and cognitive performance. Two-hundred and forty-one adults aged ≥ 60 years who had serum vitamin B12 serum levels measurement were included. Physical and cognitive evaluation was carried out, and three groups were formed: normal cognition (NC), mild cognitive impairment (MCI) and dementia. Vitamin B12 levels were classified as sufficiency (> 400 pg/mL), subclinical deficiency (201-400 pg/mL), and absolute deficiency (≤ 200 pg/mL). Multivariate linear regression analysis was used to evaluate the association between cognitive function and vitamin B12 levels after controlling for confounding variables. Mean age was 81.4 ± 8.0 years; 68% were females; 17.8 % and 39.8% had absolute and subclinical vitamin B12 deficiency, respectively; 80 individuals (33%) met the criteria for MCI, and 70 (29%), for dementia. Those with MCI and dementia had lower vitamin B12 levels in comparison with those with NC after adjusting for age, gender and educational level (p = 0.019). A statistically significant association was observed between global cognitive performance and levels of vitamin B12.