METFORMIN VÀ THIẾU VITAMIN B12

Abstract

Diabetes mellitus has sharply risen in prevalence in the twenty-first century, resulting in a range of complications that impact patients’ health and impose considerable burdens on healthcare systems and national economies. Based on the guidelines of the European Association for the Study of Diabetes (EASD), the American Diabetes Association (ADA), and the Ministry of Health, metformin is recommended as the first-line medication for controlling of blood glucose levels. This offers benefits in lowering the risk of microvascular complications, cardiovascular disease, and mortality. However, recent studies have showed a correlation between long-term metformin usage and vitamin B₁₂ shortage. The exact mechanisms behind metformin-induced vitamin B₁₂ deficiency are not fully understood, but they mainly relate to disturbances in the absorption and metabolism of vitamin B₁₂. Lack of vitamin B₁₂ can lead to hematologic and neurological disorders, along with the accumulation of homocysteine, resulting in hyperhomocysteinemia. The limited specificity of available biomarkers and the lack of consensus on its definition make diagnosing vitamin B₁₂ insufficiency especially difficult. A definitive diagnosis of tissue vitamin B₁₂ deficiency should combine at least one circulating vitamin B₁₂ biomarker (such as serum vitamin B₁₂ or holotranscobalamin) with a functional vitamin B₁₂ biomarker (such as methylmalonic acid or homocysteine). At present, there are no specific guidelines for screening for vitamin B₁₂ deficiency in patients undergoing metformin therapy. According to the British Society for Haematology, there are no recommendations for prophylactic vitamin B₁₂ supplementation for such patients. However, those diagnosed with metformin-induced vitamin B₁₂ deficiency should receive prompt vitamin B₁₂ supplementation.