Hello, I am recovering from a long long term B12 deficiency that it took FOUR doctors and what seemed like an eternity to diagnose. The peripheral neuropathy began as numbness and tingling in my hands and feet. After awhile there was burning pain at the right of my spine and it turned into an electrical current that went into the base of my skull and made my face numb. The reason that they couldn't seem to diagnose my deficiency was that the labs showed B12 at the extreme low end but not below what they consider normal. The damage to my spine and brain did not show up on the MRIs. Because of that I was completely written off. I was told that I have bipolar disorder, irritable bowel, and to take a montly B12 shot. Now I am fighting to find the cause of the malabsorption, but even the gastroenterologist doesn't believe that B12 deficiency can cause that amount of neuropathy before the B12 level goes below that ridiculous low value. Somehow I will find the cause of the deficiency, but it has taken years and I have lost chances at the career of my choice. For anyone who has neurological damage and is/was not believed, you are definitely not alone. Unfortunately for me I now have a "label" in my medical file as not being mentally well because I came into the doctor's office with mood swings, mental confusion and memory loss.