Answer
Yes. Metformin can reduce vitamin B12, particularly with prolonged use or other risk factors. Anaemia, a sore tongue, marked tiredness, numbness or tingling should prompt review.
Sources for this answer
- Synjardy film coated tablets — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.