Association between metformin use and vitamin B12 deficiency in patients with type 2 diabetes

Abstract

Metformin is one of the most widely used oral antihyperglycemic agents. Adverse effect of metformin is disturbance in vitamin B12 metabolism associated with low serum vitamin B12 level. Vitamin B12 hypovitaminosis is accompanied by peripheral neuropathy. The long-term use can cause anemia and increase the risk of depression, cerebrovascular and neurodegenerative diseases. Clinical studies and meta-analyses have constantly confirmed the association between metformin use and vitamin B12 hypovitaminosis. It was shown that every 25 pmol/l increase in B12 level was associated with a 6% reduction in the risk of neuropathy. The application of B12 would help compensate the disturbances in vitamin B12 metabolism caused by metformin.

Keywords

• diabetes mellitus
• metformin
• vitamin B12 hypovitaminosis