Can You Take Metformin (Off-label) and Vitamin B12 Together?

Dose or timing may matter

The short answer

Metformin reduces vitamin B12 absorption by up to 30% through interference with calcium-dependent B12-intrinsic factor complex uptake in the ileum.

How to arrange timing

Monitor B12 levels when using metformin. Consider supplementing with higher doses of B12.

Reference

Reference noted for this combination: Aroda VR, et al. J Clin Endocrinol Metab. 2016

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.