I know this is an old thread, but after reading the whole thing, I find many similarities to @Kittygiggles. I was recently diagnosed with a rare genetic condition called hypophosphatasia, which can cause high levels of B6 amongst other symptoms. I landed on this thread because I was looking at the symptoms of high levels of B6 and possible solutions. While hypophosphatasia is rare, it might be worth looking into it. The genetic testing for this condition is quite expensive and most doctors have never even heard of it, but if that's not possible, the only other indicator is a low level of ALP, which in included in a liver function panel. I'm not sure if this will help, but I figured I'd put the info out there in case anyone wanted to consider other possibilities.