Supplement riboflavin to fix the MTHFR polymorphism

Improving riboflavin status (via supplementation) may make MTHFR work like it should, since the 677C→T mutation simply reduces its ability to bind with its riboflavin-dependent cofactor (FAD).

It’s literally addressing the cause (making MTHFR work like normal) rather than the symptom (supplementing with 5-methyl THF because you make less of it).