Prevalence of Vitamin B12 Deficiency in Patients with type 2 Diabetes Mellitus on Metformin

Abstract

Background: Type ₂ diabetes mellitus (T₂DM) is a common public health problem in metabolism. Metformin is the oral hypoglycemic agent used as a first line together with life style modification in type ₂ diabetes patients worldwide. Continuous metformin therapy increases the risk of vitamin B12 insufficiency, and its medical consequences in T₂DM patients.

Objective: To detect the prevalence of serum vitamin B₁₂ deficiency in T₂DM who has been treated with metformin in Erbil Province.

Patients and Methods: The study involved 200 cases (100 patients and 100 controls) that met the study's basic criteria. A completed questionnaire, and a blood test for serum vitamin B₁₂ levels were performed. A deficiency of vitamin B₁₂ is defined as <160 pg/mL in serum vitamin B₁₂.

Results: Deficiency of serum vitamin B12 was found in 48% of patients (n=48), while HbA1c levels had no impact on this finding. In T₂DM level of serum vitamin B₁₂ that has been on metformin at a dose of ≤ 1 gm/ day shows a significant difference with those patients with no history of metformin use.

Conclusion: Low levels of serum vitamin B₁₂  came as a result of the overdosing of metformin for long period of treatment.