MTHFR and Stroke: The largest study conducted to date investigating PWV with respect to the MTHFR genotype is a substudy of the China Stroke Primary Prevention Trial (CSPPT),16 an RCT investigating the effect of 0.8‐mg folic acid plus enalapril versus enalapril alone in reducing the occurrence of first stroke in hypertensive Chinese patients, stratified by the MTHFR genotype.33