those who lack vitamin B6,B12 and folates.
those who have excess animal protein intake.
elderly males.
those with impaired renal functions
those with impaired thyroid functyions(hypothyroidism).
those on drugs like pheytoin,methotrexate and theophylline.

How does Homecyseine produce atherosclerosis?

it generates free radicals eg.superoxides and hydrogen peroxide which damage the endothelial cells of the blood vessels.
it encourages formation of blood clots
it prevents small arteries from dilating and makes them more vulnerable to obstruction from blood clots
it increases the smooth muscle cells in the arterial wall
it causes platelet aggregation
when infused into baboon arteries,it causes the endothelial cells to slough off,resulting in lesions similar to human atheromas.

When blood homocyseine level increases:-
for every 5 umol/L increase there is a 1/3 increase in the chance of one dying of coronary heart disease.
there is increased risk of atherosclerosis,even if blood cholesterol level is not raised!

You must take vitamin B-complex regularly to reduce the Homocysteine level in your blood!