I know 300mg of Pyridoxine (much less 1000mg) is way high and has the potential for peripheral neuropathy after a few months; I don't know how P5P compares,
Personally I don't know if you have got the pyridoxamine facts right (I hope not, I wish it wasn't neurotoxic like pyridoxin), but most people say P5P as the active form of b6 is not neurotoxic. I've even heard that pyridoxin competes with P5P and is therefore neurotoxic.
Oh, no!
Neurochem Pathol. 1985 Fall;3(3):159-67.
Neurotoxicity of pyridoxine analogs is related to coenzyme structure.
Windebank AJ.
In very high doses, pyridoxine is neurotoxic in humans and other animals. Using morphometry and a model system of dorsal root ganglion neurons in culture, we found that several analogs of pyridoxine were neurotoxic
in vitro. Those that may be converted into active coenzymes--pyridoxal, pyridoxine, and
pyridoxamine--were almost equal in toxicity. Pyridoxic acid, which is not active, was nontoxic. Pyridoxamine 5-phosphate, which cannot enter cells, also was nontoxic. Several hypotheses that link coenzyme function to toxic effect are described.
Oh, yes?
J Appl Toxicol. 2004 Nov-Dec;24(6):497-500.
Pyridoxine (vitamin B6) neurotoxicity: enhancement by protein-deficient diet.
Levine S, Saltzman A.
...
The vitamers related to pyridoxine (pyridoxal, pyridoxamine) and the coenzyme (pyridoxal 5-phosphate) did not cause clinical signs or lesions similar to those produced by pyridoxine even when injected in maximum tolerated doses. Neither a protein-deficient diet nor bilateral nephrectomy changed the results with the vitamers.
Edited by kismet, 20 January 2009 - 03:18 PM.