Thanks for the responses. The family doctor 5 years ago said it was idio pn based on my description (numbness, tingling, burning, etc) and because she did a touch test and a balance test. She said it was idiopathic because my glucose test was normal.

I'm in the process of getting a new family doctor who is with Ohio State University Family Practice. My appt with him is in 2 weeks but before then I thought I may as well try B12.