Oxidative Stress and Vitamin E Requirements

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00067899

Enrollment

Registered

2003-09-08

Start date

2000-09-30

Completion date

2005-12-31

Last updated

2013-06-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Smoking

Keywords

cigarette smoking, tocopherol, bioavailability, metabolism, oxidative stress

Brief summary

The purpose of this study is to determine if oxidative stress derived from cigarette smoking increases vitamin E requirements. The study will also assess the role of vitamin C in modulating vitamin E requirements. Vitamin E requirements will be assessed by measuring vitamin E in plasma as well as by measuring the excreted vitamin E metabolite in the urine.

Detailed description

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.

Interventions

DRUGVitamin E with and without Vitamin C

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

DOUBLE

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

Healthy volunteers

Yes

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

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026