Oxidative Stress and Vitamin E Requirements

We will be investigating the fractional disappearance rate of tocopherols in cigarette smokers compared to nonsmokers. This will be accomplished by supplementing individuals with deuterium labeled alpha- and gamma-tocopherols. Quantification of plasma tocopherols as well as urinary metabolites, alpha- and gamma-carboxy ethyl hydroxychromanol, will be determined using liquid chromatography/mass spectrometry analysis. In addition, the role of vitamin C as it pertains to its influence on the fraction disappearance rate of vitamin E will also be evaluated.

Inclusion criteria

• non-smoking status or smokers (more than 1 pack per day)
• age: 18-35 y
• stable body weight, ranging between 80% and 130%,
• maintenance of normal exercise and activity patterns
• total cholesterol ≤ 7.758 mmol/L (300 mg/dl)
• triglyceride concentration ≤ 3.387 mmol/L (300 mg/dl)

Subjects will be excluded if they fulfill any one of the following:

• antioxidant supplement users
• resting blood pressure above 160/105 mm Hg
• engaged in aerobic activity more than five hours per week
• vegetarian or other restrictive dietary requirements
• fasting blood glucose concentration of ≥ 7.77 mmol/L (140 mg/dl)
• history of diabetes or uremia
• other known metabolic disease or medication use known to affect lipid metabolism