Like most of us out there, it has been a matter of trial and error without a lot of help from anyone. If you like you can click on my id to see previous posts as I struggled along. I have tried many, many things. Long and short of it, I seemed to notice improvements (judged by peoples reactions), slowly as I tried different supplements. The other thing is that when I ran out of particular ones and failed to replace them, the reactions came back.
The essentials I am down to are Zinc (must be an available form ex. picolinate, citrate, orotate etc ( 30 to 50mg per day), Vitamin B6 in the form of P5P (50mg per day -this is directly available to the body without having to be metabolized).
The other B vitamins should also be supplemented so a good quality multivitamin should be included. I also use digestive enzymes, probiotics and caprylic acid or coconut oil which I feel have resolved Candida and sinus problems which were also side issues. I came to these by trial and error and only lately have added P5P after reading about pyroluria and being amazed at how my problems lined up with it, and I had accidentally come upon the exact same protocol that is recommended except that I had never heard of P5P, I was instead using a multivitamin with high content of B vitamins, so I added it, but if you use it make sure you look at the dose of the other supplements B6 so as not to overdo it.
I realize that this may not be the answer to everyone's situation, but if it is helpful, I will be glad to know I was of help to someone.
I could write more, but those are the essentials. Please supplement this information with your own reading, bearing in mind that I am no doctor, just a person who has been in your shoes trying to share my experience.