Patients will be screened for carotid intima-media thickness at home or at schools in mobile vans equipped with portable ultrasound equipment. After 12 months, those patients above the age and sex-adjusted 66th percentile at Screen I will be re-screened (Screen II), and those showing the greatest progression in intima-media thickness will be invited to participate in a trial run-in to assess vitamin E compliance. Patients will be randomized to the following four groups: 1) vitamin E (573 mg/day); 2) vitamin C; 3) Vitamin E and C combined; and 4) placebo. Common carotid artery intima-media thickness will be observed by ultrasound at 12- and 24-month follow-ups. The primary outcome is 24-month rate of change in average common carotid artery intima-media thickness.