Vitamin B 12 Levels in Patients with Type 2 Diabetes Mellitus on Metformin

Abstract

Vitamin B12 is required for proper hematopoeisis, cardiovascular and neurocognitive function. Vitamin B12 deficiency is highly prevalent among patients with type 2 diabetes mellitus (T2DM) on metformin therapy. Aim: This study was carried out to evaluate the serum levels of vitamin B12 in patients with T2DM on metformin therapy. Material and methods: Hundred patients with T2DM within the age group of 45-80 years were recruited into this cross-sectional study. All the patients were on metformin therapy for a minimum of 5 years. Results: Vitamin B12 deficiency and borderline deficiency observed were 10.6% and 29% and 60.4% did not have vitamin B12 deficiency. B12 levels were lower in patients with more than 10 years of duration of diabetes and was statistically significant with a p value of 0.004. The average B12 levels in patients on metformin dose of >1,000 mg was 349 pg/dL and in patients with metformin dose above 1,000 mg was 215 pg/dL. The difference between the two groups was statistically significant with a p value of <0.002. Conclusion: There is a high prevalence of B 12 deficiency among diabetic patients. It is important to screen for vitamin B12 deficiency before initiating metformin and later annually.