Vitamins for Stroke Prevention / 대한뇌졸중학회지

ABSTRACT

For the past 20 years, it has been suggested that B vitamins (vitamin B6, folate, vitamin B12) and antioxidant vitamins (vitamin A, vitamin C, vitamin E) can prevent cardiovascular disease. Many observational studies reported a consistent dose-related association between homocysteine levels and cardiovascular morbidity and mortality. Homocysteine can be easily lowered by supplementation of vitamin B6, folate, and vitamin B12. Because the vitamins are inexpensive and relatively safe, such therapy would be highly cost effective. However randomized clinical studies using vitamin B6, folate or vitamin B12 supplementation failed to show benefit in preventing cardiovascular disease despite adequate lowering of homocysteine. Similarly, the role of anti-oxidant vitamins was linked to prevention of cardiovascular disease by limiting oxidation of low density lipoprotein cholesterol. In large observational studies, higher intake of anti-oxidant vitamins from diet or supplement was associated with decreased risk of coronary artery disease in men and women. However, a series of large randomized trials demonstrated no benefit from these anti-oxidant vitamins. Instead, several meta-analyses showed that supplementation of carotene, vitamin C or vitamin E increased cardiovascular mortality or all cause mortality. Considering currently available evidences, vitamins taken in excess of the dose required to prevent deficiency states are not beneficial in preventing cardiovascular disease and may harm people.