Vitamin E and folic acid are out of fashion in preventing cardiovascular events.

Some years ago after a visit with the cardiologist, one often stopped by the drug store to pick up a bottle of vitamin E or folic acid. No more! like fashion, the trend has since reversed; most trials have shown negative results of late.

Reported in the New England Journal of Medicine (2000; 342:154) that in patients with high risk for cardiovascular events, treatment with vitamin E for a mean of 4.5 years has no effect on the cardiovascular outcome. Vitamin E and beta carotene have shown no benefits for primary prevention (i.e. in preventing the first heart attack.)

Homocysteine has atherogenic (causing ‘hardening of artery’) and prothrombotic (promoting blood clots) properties. Hyperhomocysteinemia (too much homocysteine in the blood) is a risk factor for cardiovascular disease and venous thrombosis (blood clot in the vein) Using vitamin B6, vitamin B12, and folic acid can lower blood homocysteine level. Based on the following homocysteine metabolism pathway, one can see that vitamin B6, vitamin B12, and folic acid promote "homocysteine à à cysteine pathway", thereby lowering homocysteine level.
But several trials of such approach failed to show any decrease in cardiovascular events or death. The following is the conclusion in an article on NEJM 2006;354:1578.

Treatment with B vitamins did not lower the risk of recurrent cardiovascular disease after acute myocardial infarction. A harmful effect from combined B vitamin treatment was suggested. Such treatment should therefore not be recommended.

However, those with venous thrombosis and elevated blood homocysteine level, treatments with folic acid (1 mg/day), vitamin B6 (10 mg/day), and vitamin B12 (0.4 mg/day) are recommended. And screening hyperhomocysteinemia in patients with otherwise unexplained venous thrombosis is recommended.

Certain drugs used to treat hypercholesterolemia (high blood cholesterol level), such as fibrates and nicotinic acid, can raise homocysteine levels by 30%; however, the clinical significance of this is uncertain.

With the conflicting and ever shifting data of these vitamin supplements like a fashion, the best policy is to pay attention to those well-established cardiovascular risk factors including smoking, diabetes (which is considered a coronary equivalent), dyslipidemia, hypertension, and older age. (here is another good reason to stay forever young)