(P03-021-24) Association of Dietary Folate and Vitamin B12 Intake With Cognitive Impairment in Taiwanese Elderly

Objectives: To investigate association between dietary intakes of one-carbon nutrients (folate and vitamin B12) and cognitive impairment in Taiwan elderly.

Methods: It's a case-cohort design to select Taiwanese Elderly from the One-Carbon Nutrition and Alzheimer’s Disease Prevention cohort study. Subjects were recruited from the Neurology Clinics of National Taiwan University Hospital and Fu Jen Catholic University Hospital from 2019-2024. According to Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) Scale, or/and MRI examination, the subjects were divided into mild cognitive impairment (MCI) including very mild Alzheimer’s disease group (n = 47), mild or above Alzheimer’s disease group (AD, n = 32), and subjected cognitive decline group (SCD, n = 80). A general questionnaire was used to collect the basic information. A semi-quantitative dietary frequency questionnaire was used to assess the intake of folate and B12. Blood samples were collected for biochemistry measurement.

Results: For SCD, MCI, and AD groups, dietary insufficiency rate (< RDA) was 28%, 45%, and 34% for folate, and was 20%, 19%, and 34% for vitamin B12. AD vs. SCD and MCI subjects had lower vitamin B12 intake (p =0.049) with elevated Hcy concentrations (p=0.046). Energy-adjusted vitamin B12 intake (R=0.2, p=0.01) and plasma Vit. B12 levels (R=0.16, p=0.042) were positively correlated with MMSE score, whereas plasma homocysteine (Hcy) was inversely correlated with MMSE score (p=0.016). Multiple Linear regression models showed that increased Vit. B12 intake was associated with higher MMSE score (β=0.26, SE=0.0007, p=0.02) in SCD group after adjustment for age, sex, education level, and plasma Hcy level. ROC analysis showed that dietary folate intake at the level of < 463 ug/day may predict cognition impairment (MMSE < 26) (AUROC: 0.623, SEN = 60.4%, SPE = 67.9%, p = 0.01). Vit. B12 intake at cut-point < 3.9 ug/day can predict cognition impairment (MMSE < 26) (AUC: 0.66; SEN = 66.0%, SPE = 71.7%, p < 0.001).

Conclusions: Increased dietary intake of vitamin B12 was associated with improved cognition function among the Taiwanese elderly. The current RDA of folate (400 ug/day) and B12 (2.4 ug) for Taiwanese elderly may not be sufficient to minimize the cognition decline according to the ROC cutout measurement.

Funding Sources: Taiwan National Science and Technology Council