I've been on B12 shots for 7 years. I complained to my doctor 5 years before then that I was fatigued,  legs were heavy, numbness..... He blamed getting older, diabetes, a blood pressure pill.... I was the hospital for another reason when a student doctor asked if I always walked funny; told him I hadn't noticed, but he said to ask for a B12 blood test. It came back at 60; normal range is 150- 900 PMOL/L. I now maintain levels around 800. Found out the cause is that Metformin (diabetic drug) interferes with the intrinsic factor that is involved in B12 absorption in the small intestine. I had been on it for 10 years before being diagnosed with severe B12 deficiency. I now have permanent nerve damage in  my legs and quite a balance problem. 30% of the population is affected with this absorption problem; also the older you get, the less B12 is absorbed.

My doctor was unaware of the metformin connection; as was a good friend of mine who was a public health nurse  dealing mainly with seniors. She said that explains why so many of her diabetic patients needed B12 shots.

gene champ, I now self inject IM, 1ML of Cyanocobalamin (B12)  once per week. It is available over the counter at most pharmacies; usually get mine at Walmart. Yes, I use a syringe, similar to insulin syringe, just longer needle. You should start feeling better within a week. Hopefully you have no permanent damage.

I never thought that I would have a B12 deficiency; as a beef farmer probably eating beef 10 times a week.