The incidence of a second stroke in patients who have had a first stroke is between 7 and 10 percent per year. Myocardial infarction (heart attack) as a complication of stroke adds to stroke death and disability. Because homocysteine may be a major contributor to stroke, its reduction by appropriate intervention with vitamin supplements could reduce the impact of recurrent stroke, myocardial infarction, and vascular death. The purpose of this trial is to determine whether a multivitamin containing high-dose folic acid, pyridoxine, and cyanocobalamin, in addition to best medical/surgical management and risk factor modification, reduces the recurrence of stroke or occurrence of myocardial infarction in stroke patients with elevated homocysteine levels.