Association of vitamin D and vitamin B12 with cognitive impairment in elderly aged 80 years or older: 

05.03.2019

Publisert feb. 2019

AbstractBackground: The present study aimed to assess the association of vitamin Dand vitamin B12with cognitive impairment in elderly people.Methods: The data were obtained from a cross-sectional study that includedindividuals aged 80 years or older living in the urban and rural areas of thecities of Sideropolis and Treviso in the state of Santa Catarina, Brazil. Intotal, 165 elderly people were included in the analysis. The outcome of cog-nitive decline was assessed by the Mini-Mental State Examination. VitaminD and vitamin B12levels were measured from blood samples. The socio-demographic, anthropometric and health variables used in the analysis werecollected from a questionnaire. Crude and adjusted analyses of the relation-ship between vitamins D and B12and cognitive decline were performedusing a Poisson regression model.Results: The prevalence of cognitive decline was 35.2%. In the adjustedmodel, individuals who had vitamin D levels >19 ng mL1showed a lowerprevalence of cognitive decline (prevalence ratio = 0.59; 95% confidenceinterval = 0.39-0.87). Those participants who had vitamin B12levels of≥496 pg mL1had a higher prevalence of cognitive decline (prevalenceratio = 1.90; 95% confidence interval = 1.08-3.36).Conclusions: The present study showed that individuals aged ≥80 yearswho had vitamin D levels of ≤18 ng mL1had a higher prevalence of cog-nitive decline even after adjustment for potential confounders. In addition,the study demonstrated that vitamin B12levels of ≥496 pg mL1in thispopulation were also a risk factor for cognitive decline. A cross-sectionalanalysis does not enable the inference of a cause-effect relationship andadditional studies are needed to understand these relationship.