The treatment of Pyrrole Disorder (PD) AKA Pyroluria involves amounts of vitamin B6 in various forms which are many times the recommended daily allowance (RDA). With large amounts of B6 comes the possibility of peripheral neuropathy. This can occur even with small amounts if certain gene mutations (SNPs) are present, which is why it is not recommended to be taking supplements without testing and direction from a trained competent physician.
It has been found that a paradox occurs with very high amounts of pyridoxine (B6) which causes symptoms of B6 deficiency, which is peripheral neuropathy. This is because high levels of B6 can saturate or 'block' enzymes which are needed to turn it into the active pyridoxal-5-phosphate used by the body, leading to deficiency symptoms. Because of this pyridoxal-5-phosphate (PLP or P5P) is prescribed along with large-dose pyridoxine (B6) usually to avoid the deficiency symptoms.