Folic acid, homocysteine, and cardiovascular disease: judging causality in the face of inconclusive trial evidence

Abstract
Cohort studies Meta-analyses of cohort studies show significant positive associations between serum homocysteine concentrations and ischaemic heart disease events (fatal and non-fatal myocardial infarction and sudden cardiac death) and stroke. A 3 µmol/l decrease in serum homocysteine (achievable with 0.8 mg/day folic acid) lowers the risk of myocardial infarction by 15% and stroke by 24%.1 3 These estimates were adjusted for confounding by other cardiovascular risk factors.