Don't Routinely Check B12 Levels in Most Patients Taking Metformin
You'll get questions about metformin and vitamin B12 deficiency.
Up to 1 in 14 patients taking metformin for about 4 years develop B12 deficiency. It's probably even more common with longer use.
Consider whether metformin may be contributing if you happen to find macrocytic anemia on a routine CBC...or in patients with neuropathy.