Should we follow the guidelines on vitamin B12 deficiency and diabetes? A retrospective analysis of data from middle eastern population

ABSTRACTBackground Vitamin B12 is a micronutrient required for hematopoietic, neuro-cognitive and cardiovascular function. Biochemical and clinical vitamin B12 deficiency has been recognized in patients with type 2 diabetes mellitus. One of the adverse effects of long-term metformin use is vitamin B12 malabsorption. Aim of the study was to assess the state of vitamin B12 deficiency in people with type 2 diabetes and to ascertain the relationship between vitamin B12 status, metformin use and peripheral neuropathy. It is a retrospective study that was conducted on 8040 subjects included 2126 type 2 diabetic patients, and 5914 nondiabetic individuals. Personal information, medical history, including metformin and multivitamin therapy use as well as the existence of clinical peripheral neuropathy, were all included data. For the purpose of measuring the amount of vitamin B12, blood samples were taken. Serum B12 levels