Vitamin B12, Homocysteine, and Cognitive Function in the Older Adults Attending a Tertiary Geriatric Psychiatry...

Cognitive impairment in older adults has been linked to low serum Vitamin B12 (B12) and elevated homocysteine (HCY) levels, but evidence remains inconclusive. This study examined their relationship with cognitive impairment among older adults in India.

This retrospective case note-based study included 96 subjects: cognitively normal (n = 21), Alzheimer's disease (AD; n = 42), and other cognitive disorders (n = 33). The mean age was 70.1 (± 8.9) years, with 58% males. Cognitive function was assessed using the Hindi Mental Status Examination (HMSE). Serum B12 (pg/ml) and HCY (micromol/L) levels were measured. Pearson's correlation, multiple linear regression, and bootstrapped mediation analyses were performed.

Elevated HCY (>15 micromol/L) was seen in 72%, and low B12 (<200 pg/mL) in 33%. The mean HMSE score was 16.9 (± 8.5). No significant correlation was found between HMSE scores and HCY (r = -0.006, p = 0.95) or B12 (r = 0.12, p = 0.23). HCY levels were higher in cognitively impaired groups than controls, but not significantly. Regression analysis showed gender as a significant predictor, while B12, HCY, and age were not.

B12 and HCY levels were not independently associated with cognitive performance. No significant moderation effect between B12 and HCY on HMSE scores was observed.