The purpose of this study is to examine whether vitamin B supplementation will reduce the progression of early atherosclerosis in individuals over 40 years old and without clinical evidence of cardiovascular disease (CVD).

The primary hypothesis to be tested is that daily vitamin B supplementation reduces progression of early atherosclerosis. Ultrasonography will be used to measure the rate of change in the thickness of the carotid artery and CT will be used to measure coronary and aortic calcium. The beneficial effects of vitamin B supplementation are expected to occur with or without a change in LDL-C levels.

A total of 506 men and women will be randomized to receive either 1) vitamin B supplementation consisting of folic acid 5mg, vitamin B12 0.4mg, and vitamin B6 50mg, or 2) a matching placebo. Participants will receive ultrasonography at baseline and every 6 months for 2.5 to 4.5 years, and CT scan at baseline and end of study (2.5 to 4.5 years).

Inclusion Criteria:

• Male or female (postmenopausal)
• 40 years or older
• Fasting plasma homocysteine 8.5 micromoles per liter (µmol/L) or greater

Exclusion Criteria:

• Any clinical signs or symptoms of cardiovascular disease (CVD)
• Diabetes mellitus or fasting serum glucose 140 mg/dL or greater
• Triglyceride (TG) levels 500mg/dL or greater
• Serum creatinine greater than 1.6 mg/dL
• Uncontrolled hypertension (systolic blood pressure 160 mmHg or greater and/or diastolic blood pressure 100 mmHg or greater)
• Thyroid disease (untreated)
• Life threatening disease with prognosis less than 5 years
• Alcohol intake greater than 5 drinks per day (1 drink = 1 1/2 oz distilled spirits, 4 oz wine, or 12 oz beer) or substance abuse (intravenous drug use, cocaine use)