Prevalence of vitamin B12 deficiency in type 2 diabetes patient treated with metformin

Background: Metformin-induced vitamin B12 deficiency was shown by several studies with a prevalence estimate ranging from 5.8% to 52%. Objectives: This study aimed to assess the prevalence of vitamin B12 deficiency in patients with Type 2 diabetes mellitus (T2DM) on metformin. Methods: A cross-sectional observational study was done on 347 type 2 diabetic patients who were using the drug 'metformin' for at least six months and who attended a specialty diabetic clinic at Taif city of Saudi Arabia. Information on patients age, gender, type of metformin, assay results for Vitamin B12, and medical history were obtained. Vitamin B12 levels in serum were tested. Results: The mean age of the patients was found to be 58.10 +/- 14.31, and the mean Vitamin B12 level was found to be (464.99 +/- 419). The prevalence of vitamin B12 deficiency among participants was 10.4%. Patients with borderline levels were approximately 20.2% and the remaining 69.5% had normal vitamin B12 levels. No statistically significant difference was found between different age groups according to the mean level of Vitamin B12. Those who were on Metformin 1 mg and Metformin 750 mg had a statistically significant higher percentage of those who had deficient Vitamin B12 (<200) than those on Metformin 500 mg. Conclusions: Vitamin B12 supplementation should be prescribed for diabetic patients to prevent the occurrence of vitamin B12 deficiency complications.