To explore the association between vitamin B12 deficiency and dementia in patients at high risk for vitamin B12 deficiency.

Chart review.

Emergency, critical care/trauma, neurology, medicine, and rehabilitation units of two hospitals in Southwestern Ontario, Canada.

Adult patients (n = 666) admitted from 2010 to 2012. Data collection included: reason for admission, gender, age, clinical signs and symptoms of B12 deficiency, serum B12 concentration, and B12 supplementation. Patients with dementia were identified based on their medication profile and medical history. Vitamin B12 deficiency (pmol/L) was defined as serum B12 concentration <148; marginal deficiency: ≥148–220 and adequate >220. Comparisons between B12-deficient patients with and without dementia were examined using parametric and non-parametric tests.

Serum B12 values were available for 60% (399/666) of the patients, of whom 4% (16/399) were B12-deficient and 14% (57/399) were marginally deficient. Patients with dementia were not more likely to be B12-deficient or marginally deficient [21% (26/121)] compared to those with no dementia [17% (47/278), p=0.27)]. Based on documentation, 34% (25/73) of the B12-deficient and marginally-deficient patients did not receive B12 supplementation, of whom 40% (10/25) had dementia.

In this sample of patients, there was no association between B12 deficiency and dementia. However, appropriate B12 screening protocols are necessary for high risk patient to identify deficiency and then receive B12 supplementation as needed.