Folic acid does not improve endothelial function in healthy hyperhomocysteinaemic subjects

Folic acid supplementation lowers total plasma homocysteine (tHcy) and improves endothelial function in individuals with coronary artery disease (CAD) and in those with additional CAD risk factors. In the present study, we assessed whether endothelial function is impaired in healthy subjects with hyperhomocysteinaemia but without other CAD risk factors and whether folic acid supplementation improves endothelial function in these subjects. Flow-mediated dilatation (FMD) of the brachial artery was performed on 26 healthy subjects, age 49±2 years (mean±S.E.M.), with high tHcy (15.6±1.5 mmol/l) and 16 healthy age-matched subjects with low tHcy (7.9±0.6 mmol/l; P