Lowering homocysteine levels with folic acid and vitamin B12 supplements does not reduce the risk of cardiovascular events or stroke in patients who have suffered an MI, a major study has concluded. it would appear that SEARCH has finally laid the homocysteine theory to rest. Raised levels may be associated with increased cardiovascular risk but this would not appear to be a causal association. The authors also noted that a recently submitted meta-analysis of individual patient data from eight homocysteine lowering trials, including SEARCH, with data on 37,485 individuals, confirms that folic acid supplementation has no significant effect on major vascular events, RR 1.01 (95% CI: 0.97-1.05).