MTHFR gene polymorphisms can explain persistent high blood pressure unresponsive to diet and exercise.

“So my mother-in-law got genotyped and we found out that she is homozygous for MTHFR, meaning that her MTHFR enzyme only is working at about 10 to 20% efficiency. She's always had really high blood pressure, to the point where doctors were wanting to get her on medicine for it and she's always refused. Nothing she did . . . she's done various diets, lots of exercise, lots of things she's tried, nothing has gotten her into a normal range until we identified she had MTHFR, got her supplementing with 5-methylfolate and methylcobalamin.”