Prevalence, associated factors and impact of vitamin B12 deficiency in elderly medical inpatients

Abstract Methods This retrospective cohort study investigates the prevalence of vitamin B12 deficiency, the associated factors and its relation to frailty and functional status. Data were collected from elderly inpatients (≥ 65 years) sequentially admitted to the Internal Medicine Department of a tertiary university hospital. Clinical and laboratory characteristics, including age, gender, somatometric data, cause of admission, past medical history, chronic medication use, and laboratory tests, were recorded. Frailty and functional status were assessed using the Fried Frailty Scale (FFS), Clinical Frailty Scale (CFS), Barthel Index, and Katz Index. Vitamin B12 levels were categorised as deficient ( 300 pg/ml). Results A total of 961 patients were included; the prevalence of vitamin B12 deficiency was found in 9.1%, while 17.3% of the sample had borderline levels. Multivariate analysis identified polypharmacy (≥5 drugs), low albumin levels/GNRI, and nursing home residency as independent factors associated with low B12 levels. Multivariate analyses showed that B12 deficiency was significantly associated with higher frailty rates and lower functional status. Conclusion Vitamin B12 deficiency is prevalent among hospitalized elderly patients and is significantly associated with increased frailty and reduced functional status. These findings underscore the importance of routine screening for B12 deficiency in this vulnerable population to improve clinical outcomes and quality of life.