i am low in vitamin B12.the doctor prescribed me 8 injections during this month.Yesterday I started with the first one and I got heartburn and like an acid feeling in my throat all day and night long.Also I felt I was full of gases that I couldn't throw away? Anybody has had an experience with vitamin B12 like mine??Please help because I have to put the other shot on Monday and I am starting to doubt about doing it!!ThanksAnyita