The neurologist who diagnosed my fibromyalgia was very adamant about not taking more than 30mg of Vitamin B6 daily. She said that this is her protocol for all of her neurology patients as it is toxic to the nerves. She said it doesn't matter whether it is taken by itself or in a balanced multi-vitamin. Have you found any evidence of fibromyalgia being aggravated or caused by excess vitamin B6?
I find this is more a concern with higher dosing over 100 mg a day and you could bypass this issue with the Pyridoxal 5 phosphate form of B6. None the less, given the small fiber neuropathy present in FMS, you can honor your neurologists intent with using 1/2 scoop of the vitamin powder a day ~ 43 mg B6 which should be low enough for his concerns (though he says 30 mg--a bit over cautious imho). meanwhile, the nutrients in the powder help support nerve function overall.