Vitamin B12 - Glucophage XR (Metformin XR) Interaction
Herbal: Vitamin B12
Also Known As: B-12, B12, B Complex, Bedumil, Cobalamin, Cobalamin Enzyme, Coenzyme B12, Co-Enzyme B12, Coenzyme B-12, Co-Enzyme B-12, Cycobemin, Dibencozide, Dibencozida, Hydroxycobalamine, Hydroxocobalaminum, Vitadurin, Vitadurine, Vitamina B12, methylcobalamin
Drug: Metformin XR
Brand names:
Glucophage XR
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
There were no interactions found between Metformin XR and Vitamin B12. This does not mean the potential for an interaction does not exist, however. There is often a lack of studies and data surrounding traditional medicine, especially concerning drug interactions, so it is important to always consult your provider before making any changes to your medication regimen.
Pharmacist Analysis
It is important to note that this is less an 'interaction' versus a potential result of prolonged metformin use. In many individuals taking metformin, supplementing with vitamin B12 is recommended.
Metformin can lead to a reduction in vitamin B12 levels, primarily depending on the dosage and duration of use. This reduction might potentially result in a deficiency. Metformin's impact on vitamin B12 levels is thought to be related to its potential interference with intrinsic factor secretion or uptake, influence on bowel motility, and the possibility of causing bacterial overgrowth. These factors can collectively contribute to vitamin B12 malabsorption and elevated homocysteine levels.
The risk of deficiency is notably higher in individuals who have been taking higher doses of metformin for an extended period, especially those who are older or follow a vegetarian diet. It's worth mentioning that even if metformin use continues, any deficiency can be corrected with the appropriate vitamin B12 supplementation.
To ensure the well-being of individuals taking metformin chronically, it's advisable to monitor for potential signs and symptoms of vitamin B12 and folic acid deficiency. Additionally, it's recommended to encourage those on metformin to maintain a diet that includes sufficient vitamin B12 and to undergo regular checks of their serum vitamin B12 and homocysteine levels, typically on an annual basis.
- Dr. Brian Staiger, PharmDVitamin B12 Overview
Vitamin B12, also known as cobalamin, is a water-soluble vitamin crucial for several bodily functions. It plays a pivotal role in the formation of red blood cells, aiding in the prevention of anemia. Vitamin B12 is essential for maintaining a healthy nervous system and proper brain function, as it is involved in the synthesis of myelin, the protective sheath around nerve fibers. This vitamin is primarily found in animal-based foods such as meat, fish, dairy products, and eggs, making it important for vegetarians and vegans to consider supplementation. A deficiency in vitamin B12 can lead to neurological issues, fatigue, and cognitive impairment.
Vitamin B12 - More Interactions
Vitamin B12 interacts with 19 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
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Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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