"We conclude that an elevation in homocysteine concentration is associated with an acute impairment of
vascular endothelial function that can be prevented by pretreatment with vitamin C in healthy subjects. Our results
support the hypothesis that the adverse effects of homocysteine on vascular endothelial cells are mediated through
oxidative stress mechanisms. (Circulation. 1999;99:1156-1160.)"
http://circ.ahajournals.org/content/99/9/1156.short