Haven't been tested for those, but I've had my vitamin levels checked numerous times. My doc said Vitamin D was low, but not unreasonably low based on the lack of sun at the time (it was winter and I live in a perpetually overcast environment during that season). No supplements until very, very recently when I started taking B12 just in case, even though my levels are very good. Should I stop?

I recently took the advice of someone in the Neuropathy forum and made an appointment at the Peripheral Neuropathy center at Cornell medicine in NYC. Hopefully they can find the culprit.