Prevalence of vitamin B12 deficiency in type 2 Diabetes Patients Treated with Metformin in the Georgian population

This study aimed to evaluate the prevalence of vitamin B12 deficiency in individuals with type 2 diabetes mellitus (T2DM) treated with metformin in Georgia, and to compare vitamin B12 levels across eastern and western rural regions and an urban population. It also assessed possible associations with metformin dose, treatment duration, sex, and age. This retrospective cross-sectional study included 972 adults with T2DM receiving metformin (1000–2000 mg/day) for at least 12 months. The mean serum vitamin B12 level was 354.65 ± 141.93 pg/mL. Deficiency (< 200 pg/mL) was detected in 12.86% of patients, borderline levels (200–400 pg/mL) in 57.61%, and normal values (> 400 pg/mL) in 29.53%. Only a very weak association was found between vitamin B12 levels and metformin dose or duration (R² = 0.007–0.051 across regions). No significant differences were observed across age groups. Men in the urban population had higher vitamin B12 levels than women. Marked regional differences were identified: the western rural region had the highest deficiency prevalence (51%), while the eastern rural and urban regions showed lower deficiency rates (4.38% and 9.0%, respectively). Regional variation in dietary habits may partly explain these differences, though this was not directly assessed and remains speculative.