Deficiencia de Vitamina B12 relacionada al Uso de Metformina

Background: Diabetes Mellitus (DM) is a metabolic disease of diverse etiology and high prevalence worldwide. 463 million cases were estimated in 2019, a number that tends to increase by year. Metformin is the most widely used medication in these patients. Vitamin B12 deficiency is a known adverse effect of the latter, though it has been poorly studied. Factors such as age, sex, dose, duration of treatment, among others have been related to the development of this complication.   Objective: Collect and synthesize up-to-date information about vitamin B12 deficiency related to metformin use, its mechanism and related risk factors.   Design: Review articles, research papers and meta-analyzes from scientific databases such as PubMed, Scielo, Cochrane and Science Direct were collected. The selected articles were published between 2010 to 2020.   Conclusion: Screening recommendations for vitamin B12 deficiency in metformin users are not yet clear and are not in guidelines. Variables such as long term usage of metformin and dose administered are related to its development. This population benefits from monitoring and even supplementation, depending on the risk.