Objective: To cross sectionally investigate the association of serum vitamin B(12) and folate concentrations with cognitive and functional ability in the very old in the general population.
Methods: Serum vitamin B(12) and folate concentrations were assessed in 471 consenting subjects participating in the Monzino 80-plus study (mean age: 87.4 years), a door-to-door population-based survey among very old subjects living in Northern Italy. Cognitive and functional evaluations included Mini-Mental State Examination (MMSE), Instrumental Activities of Daily Living (IADL) and Spontaneous Behavior Interview-basic Activities of Daily Living (SBI-bADL).
Results: MMSE, IADL and SBI-bADL scores were all significantly correlated with folate concentrations (respectively: r = 0.36, r = -0.39, r = -0.35; p < 0.0001), while no significant associations were found with vitamin B(12) concentrations. When entered into multiple linear regression analyses with several covariates, folate showed a highly significant, curvilinear association with both cognitive and functional scores (p < 0.0001). Subjects in low and middle folate tertiles had significantly higher odds ratios for dementia (p < 0.0001; adjusted ORs = 5.40 and 6.56, lower 95% CIs 2.53 and 3.11, higher 95% CIs 12.73 and 15.29).
Conclusions: Findings of this population-based study suggest that subclinical folate deficiency may represent a risk factor for the cognitive decline associated with aging that could contribute to AD as well as other dementia development.