Metformin associated B12 deficiency.

According to the ADA guidelines, metformin and lifestyle modifications are the first line therapies in the treatment of type 2 diabetes mellitus. Metformin does, however, cause vitamin B-12 malabsorption, which may increase the risk of developing vitamin B-12 deficiency--a clinically important and treatable condition. Here we report a case of 60 year old diabetic male presenting with clinical features of Vitamin B-12 deficiency on long term metformin therapy, which was confirmed on investigations. Patient showed symptomatic improvement with change in treatment.