Metformin And Vitamin B12 Deficiency: A Concise Exploration

Type 2 diabetes mellitus (T2DM) management with metformin, a first-line oral antidiabetic, is associated with emerging concerns about potential vitamin B12 deficiency. Approximately 6% to 30% of metformin users may experience this deficiency. Recent studies suggest interference in absorption and metabolism processes, prompting exploration of underlying mechanisms. Proposed mechanisms include disruption of calcium-dependent binding, alteration in small intestine motility, changes in bile acid metabolism, enhanced liver accumulation, and decreased intrinsic factor secretion. Inhibition of calcium-dependent absorption at the terminal ileum, reversible with calcium supplementation, is increasingly recognized as a key mechanism. Studies report varying prevalence rates of vitamin B12 deficiency with metformin use, emphasizing the need for careful monitoring. Daily dose appears more strongly associated with deficiency than duration. In conclusion, this mini-review underscores the intricate relationship between metformin and vitamin B12 deficiency, emphasizing the importance of vigilant monitoring and tailored interventions for comprehensive patient care.