I used to have pains in my arms, as well as really bad back pain, dizzyness, lack of concentration etc. So I started taking B12 - about 250 - 500 mcg per day, of cyanocobalamin under the tongue, which has made the pain in my arms go away, but now I believe that it may be causing psychological side effects, such as paranoia and anxiety.

Has anyone else had this problem? Or could this be my potassium going down that is causing this anxiety?