Hi, Sushi.
My advice is to hold off on adding the 5-methylTHF. Here's why: With Dr. de Meirleir's treatment, I think you will already be getting it. It is made by some of the probiotic bacteria. I'm familiar with one case in which the person added probiotics to the simplified protocol and experienced a big reaction. Eventually, he figured out that the probiotics were effectively increasing his methylfolate dose. I also wonder whether Nexavir might contain some folate. I understand that it is a low molecular weight extract from animal liver. As such, I think it is plausible that it could contain some folate, but I've never seen a published analysis of it, so its sort of a "black box" to me.
I had a discussion with Dr. de Meirleir about this at a Ratna Ling Working Group seminar a few years ago. As you probably know, he has for many years believed that the gut and its immune system are the central issue in the pathophysiology of ME/CFS. He does not believe that the methylation cycle block is fundamental. I think his view is that the problems start in the gut, and because of things that happen there, the various aspects of ME/CFS develop, including the problems with glutathione and the methylation cycle. The first time I met him, at the AACFS conference in Madison, WI in 2004, I mentioned glutathione to him and he said, "I use it!" As you noted, he also uses hydroxocobalamin. By including hydroxoB12, sometimes glutathione, probiotics and perhaps by including Nexavir, I suspect that he is implicitly doing methylation treatment as he deals with the gut and immune problems, which are his central focus. Interestingly, Amy Yasko, from whose full treatment program I extracted the simplified protocol, recommends dealing with gut issues before going on to do treatment for the methylation cycle!
So it's starting to look to me as though the gut treatment and the methylation treatment are both important, and need to go more or less hand-in-hand, however this is done, in terms of the specifics of the treatments.
I think you are in good hands. I'm following your updates. More power to you and to Dr. de Meirleir!
Best regards,
Rich