Cognitive function and vitamin B12 and D in elders from Ecuador

Abstract

IntroductionCurrent evidence still does not support the role of vitamin B12 or vitamin D in age-associated cognitive impairment.ObjectiveEvaluate the association between vitamin B12 and D and cognitive function in elders.MethodologySample included 1733 individuals 60 years old and older, who participated in the SABE study that was carried out in Ecuador. Cognitive function was measured using abbreviated version of minimental state examination (MMSE). Vitamin B12 and D were measured in blood. Data were analyzed through linear regression models with restricted cubic splines (RCSs). Models were adjusted by sex, years of education, region (urban highland, urban coast, rural highlands, rural coast), socioeconomic status, and ethnicity.ResultsIndependently from sex, age, years of education, ethnicity, socioeconomic status and geographical zone of residence, we found that vitamin B12 but not vitamin D levels were associated with cognitive function in a representative group of Ecuadorian elders. Elders with lower levels of vitamin B12 showed lower MMSE scores in comparison to elders with higher levels of vitamin B12. Moreover, a statically significant non linear interaction was found between vitamin B12 and age with respect to cognitive function. In this way, we observed that in elders 75 years old and older whose levels of vitamin B12 were 271 pg/ml or less, the drop of cognitive function was particularly steep in comparison to elders whose levels of vitamin B12 were 647 pg/ml or more.ConclusionsLow levels of vitamin B12 but not of vitamin D are associated with low cognitive functioning.