@dont, Vitamin B6 toxicity is a known issue for causing PN. There are a couple of discussions you might find helpful.

- B-6 vitamin danger!: https://connect.mayoclinic.org/discussion/b-6-vitamin-danger/
- Body making too much Vitamin B6: https://connect.mayoclinic.org/discussion/body-making-too-much-vitamin-b6/
- Hashimoto's and B6 toxicity: https://connect.mayoclinic.org/discussion/hashimoto/

More info - B6 section it explains -- too much or too little gives neuropathy: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4199287/