Metformin is the most widely used antihyperglycemic drug in patients with type 2 diabetes (T2D). Over the past 2 decades, several studies have highlighted a substantial increase in the risk of vitamin B12 deficiency in patients with T2D on metformin therapy. This can lead to several complications and induce or exacerbate peripheral neuropathy. Despite these data, there are no definite guidelines for screening, diagnosing, and treating vitamin B12 deficiency in patients with T2D on metformin therapy. Therefore, in this narrative review, we aimed to suggest a practical diagnostic and therapeutic strategy to address vitamin B12 deficiency in patients with T2D receiving metformin treatment. Clinical evidence supporting an increased risk of vitamin B12 deficiency in patients with T2D on metformin therapy and its risk factors and potential complications are also discussed.

Citations

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  Yahya Madkhali, Sami G. Almalki
  Journal of King Saud University – Science.2025; 37: 3542024.     CrossRef
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  Kyunam Kim
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• Prevalence of Vitamin B12 Deficiency in Patients With Type 2 Diabetes Mellitus on Metformin Therapy: A Cross-Sectional Study
  Shoaib Asghar, Haider Tanvir, Asad Riaz, Muhammad Hamza Ejaz, Mamuna Akram, Al Muktadir Chowdhury Evan, Salman Shahid
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