I am 42 year old female diagnosed 2 months ago with b12 deficiancy ref. 308. I also was deficient in ferritin 39 . My methylmalonic acid was also out of range at 429 norm 87-318. My ana test was positive for sjogren's and my rdw blood count was high at 15.1%. My neurologist thinks I could have additional medical issues but thinks all values are due to b12 deficiancy which has been undiagnosed for probably 3 to 4 years. I am on a regimin of b12 injections. Daily for week 1, then weekly for 3 months, and then monthly. Also taking slow release Iron and a multivitamin. Trying to eat healthy, I have IBS and that complicates things. I am having alot of strange pains, shoulders, elbows, fingers, it comes and goes. I also have pain at the injection site about 2 or 3 weeks after each shot??? My doctor just shrugs. I don't think they know. Has anyone else on b12 injections experienced rebound symptoms? Still really tired and feeling bad although I managed to clean my house yesterday but hurt all night after.