I am an 82 year old male, former long distance runner (marathon at age 72). I had minor (needle) surgery for a painful degenerating disc about 20 years ago which gave complete relief from back pain ever since. I have had PN since 2001, which seems to have been exacerbated by running that last marathon, with numbness and tingling of the feet and hands progressively moving up the legs and arms until today the tingling encompasses my entire body, from scalp to the soles of my feet. I have experienced no pain, but have frequent painful leg/thigh cramps. No cause has been determined after years of testing by the VA Medical Center, so no treatment has been authorized. It continues to progress as the months and years roll by. I have tried supplements (R-Lipoic Acid, etc) and lately have tried magnesium oil applied topically to legs and feet (which seems to eleviate the numbness, but no way to measure this). What about Metanx? No one ever mentioned this to me and I just found mention of it in an online forum.