Hi I have pernicious anemia (my stomach doesn’t produce intrinsic factor that is needed for b12 absorption) it’s an autoimmune disease. without shots I would suffer horribly and die in about 5 years incontinent in pain and unable to move or think. I need them every other day or I get symptoms. Pain starts for me in the neck. (Without b12 the spinal cord degenerates) Before my diagnosis I was a mess. I couldn’t exercise I did not have enough blood cells. My legs hurt if I wore tight pants and I was very forgetful. I saw many doctors - blood tests did not find it - endoscopy did, Every cell needs b12. In my shots I give myself - the package slip says you cannot overdose b12 and there are no known side effects except for b12 testing being high and maybe acne. The acne is gone now after 2 years. I learned a lot at the first international b12 conference in Rotterdam last year. If you have what I have please let me know I can point you in the right direction. There are Facebook groups with 60000 patients. Most doctors usually don’t know much about this disease since it’s quite newly found and looks like many other illnesses. I learned B12 tests are not always accurate and b6 in food and iron deficiency changes the typical diagnostic tool (large blood cells) to normal size. Please don’t suffer any more. some parts of your body might not recover if you wait for a doctor to prescribe shots as frequently as I need them.