@rwinney Hi Rachel, Needless to say, I am very upset that doctors missed my low level, staring at them in the face. I am so sorry that your SFN started this way. I have large fiber, and most likely small fiber, even though the biopsies did not show it. My neuro nurse said the biopsies are not completely accurate, and all my symptoms are of small fiber. I know how sick you are, and so diligent with yourself. Wish that the doctors were half as diligent. Anyway, I will start my shots as soon as I make appointments with a lab by my house. Have no idea at this point if B12 will even help. Thanks from the heart, for responding. Rachel, this life of ours is not easy. God bless, and I will post when I know more. Lori Renee