I feel that I should put this warning out there for anyone looking to treat methylation. It has become an absolute nightmare for me and has put me at the worst healthwise I've ever been. I had a practicioner tell me to take methyl folate and b-12 based on homo a1298, but I was realtively healthy, no chronic problems (other than UTIs). Cleary, she doesn't understand methylation. Over the past couple of weeks after taking the methyl supplments several months ago, my symptoms turned into multiple chemical sensititivity after I started reacting to medications then supplements/herbs. It spread to me reacting to FOOD. The symptoms worsened to include head pressure and difficulty breathing when I ate. I lost over 10 lbs b/c I couldn't tolerate anything. I was only 113 lbs and nearly 5''6"; I am down to 102 lbs. I've gone to multiple drs. including Mayo Clinic ER and regular appts at Mayo. Everyone is clueless aside from a functional med dr. I also found. He, along with a nutritoinist I've had to seek out who understands MTHFR, both said I should have never treated methylation; I had no reason to. They both belive that gut dysbosis, adrenal and thyroid issues at play as well, so I've got to work on these, but it's difficult when unable to tolerate anything. Since taking the supplements 6 months ago, I haven't been the same. Primarily in reactions to foods. Initially, I (along with another practicioner I had to seek out) thought it was sulfur and ammonia. I only tested this using the sulfate test strips, which I question their reliability. In retrospect, I now wonder if it was histamine causing problems the entire time because: 1. I've learned that folate and b-12 increase histamine, and I began taking both without balancing it with a complete b-12 as I had been doing for years prior 2. Once I got into this mess, I ended up doing the full 23andme testing based on another practicioner's advice to see the full methylation genetic defects, turns out I had defects in the DAO genes, which regulate histamine. B/c I NEVER had a problem with histamine foods before, I believe that taking the methyl supplements may have caused this defect to become activated, which led to my inability to detox histamine. I now believe that my histamine levels are elevated b/c of the above (plus, I was eating a lot of high histamine foods this summer without realizing it), and that is part of why I'm in a mess now. Luckily I found someone on another forum that suggested the failsafe elimination diet for the chemical sensitivity. Thankfully that has helped me tolerate a few foods and has stabilized the weight loss. I have a long way to go, and I hope this resolves. I was NEVER allergic or had problems with any food/med/herb prior to this. I haven't gone to work in 2 wks either b/c my reactions have been so unpredictable; this is unlike me, as I haven't had a sick day in nearly 2 years until this.