My new neurologist also tested my B6 level and found it to be very high (toxic level). I have stopped the multivitamin with B6 with a combination of Nortripyline for about 7 weeks and the PN is has remarked improved. I might be one of those people who is particularly sensitive to B6. This is the first time anyone tested the B6. Perhaps if had been tested 8 years ago, my suffering could have been stopped.