You will see the advice to cut out gluten entirely with MTHFR all over the internet, but nobody really gives a great reason for it. In truth, gluten isn’t always the problem. With an MTHFR polymorphism, you are intolerant to folic acid, the synthetic crystalline form of folate. It makes the consequences of an MTHFR polymorphism even worse. In most developed countries wheat, wheat flour, and products made with wheat flour are fortified or enriched with folic acid, which makes them harmful for people with the MTHFR mutation. Somewhere along the way, wheat and gluten got confused because there is also so much talk about gluten being bad. Having said that, many people with MTHFR do develop a gluten sensitivity, possibly due to a reaction with the folic acid that wheat has been enriched with or possibly for the same reasons gluten sensitivities have become so common in general population. In these cases, eliminating all gluten, not just from wheat but from other sources like barley and rye, will help to lower inflammation and control symptoms as well. With MTHFR it is important to follow a good MTHFR diet plan to optimize your health.