Metformin and Vitamin B12 interaction
Metformin and Vitamin B12: the Metformin prescribing label describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Metformin (Metformin hydrochloride) label · effective 2024-11-14
Monitor hematological parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities.
Vitamin B 12 Deficiency In clinical trials of 29-week duration with metformin HCl tablets, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of patients.
Such decrease, possibly due to interference with B 12 absorption from the B 12 -intrinsic factor complex, may be associated with anemia but appears to be rapidly reversible with discontinuation of metformin or vitamin B 12 supplementation.
Vitamin B 12 Deficiency : Metformin may lower vitamin B 12 levels.
Certain individuals (those with inadequate vitamin B 12 or calcium intake or absorption) appear to be predisposed to developing subnormal vitamin B 12 levels.
Curated guidance for Vitamin B12
Metformin reduces B12 absorption; people on long-term metformin should have B12 levels checked periodically.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.