What trials have been conducted to examine the effect of homocysteine-lowering therapy on stroke risk?
Trials that have examined the effect of homocysteine-lowering therapy with B complex vitamins on the risk of stroke are inconsistent. Stroke reduction generally was found in trials in which the duration of treatment exceeded 3 years, the decrease in plasma homocysteine concentration was >20%, the region where patients were recruited did not fortify diet with folate, and the participants had no prior history of stroke.