Why you can trust Nutri Advanced  Every article on our site is researched thoroughly by our team of highly qualified nutritionists. Find out more about our editorial process.

Metformin is a widely used medication for managing Type 2 diabetes, helping to control blood sugar levels by reducing glucose production in the liver and supporting insulin sensitivity. However, studies1 have shown that metformin may lead to decreased absorption of vitamin B12 in up to 30% of users, potentially leading to a deficiency. The exact mechanism is not fully understood, but it is believed to involve the disruption of a calcium-dependent absorption process.

Why do we need vitamin B12?

Red blood cell production

Vitamin B12 is essential for the production of red blood cells. A deficiency could lead to megaloblastic anaemia, where the body produces abnormally large red blood cells that cannot function properly.

Nerve cell function

Vitamin B12 supports the normal function of nerve cells and is necessary for the production of myelin, the protective sheath around nerves that facilitates the rapid transmission of nerve impulses.

DNA replication

Vitamin B12 is crucial for DNA synthesis and replication, which is vital for cell division and growth.

Vitamin B12 deficiency symptoms

• Weakness, numbness, tingling, fatigue, dizziness.
• Constipation, loss of appetite, irritability.
• Swelling or irritation of the mouth and tongue.
• Megaloblastic anaemia.
• Impaired brain function.

How to treat B12 deficiency

If you're taking metformin and are concerned about vitamin B12 deficiency, it’s important to consult with your healthcare provider. They can monitor your blood levels of vitamin B12 and make appropriate recommendations. While supplements are not always necessary, you might choose to take vitamin B12 and folic acid supplements to support your nutrient levels. Always seek medical advice before starting any supplementation to ensure it's appropriate for your individual needs.

References:
1. Kim, J., Ahn, C. W., Fang, S., Lee, H. S., & Park, J. S. (2019). Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes. Medicine, 98(46), e17918. https://doi.org/10.1097/MD.0000000000017918)

This website and its content is copyright of Nutri Advanced ©. All rights reserved. See our terms & conditions for more detail.

Nutri Advanced has a thorough research process and for any references included, each source is scrutinised beforehand. We aim to use the highest value source where possible, referencing peer-reviewed journals and official guidelines in the first instance before alternatives. You can learn more about how we ensure our content is accurate at time of publication on our editorial policy.