I've had B12 deficiency caused by metformin taken for Type II diabetes. I saw the GP last Friday and I seem to be successfully reversing the diabetes so she is taking me off the metformin! I've got a B12 injection due this Friday which I want to take. I just wonder how long it will take without metformin before my "natural" levels of B12 stabilise? Many thanks for the help of forum members, particularly when I was first diagnosed a year ago.