The Effects of Vitamin E and Vitamin C and Exercise

Not Applicable

Terminated

• Conditions: Exercise and Non-exercise Effect Upon Vitamins E and C

• Registration Number: NCT01369043
• Lead Sponsor: USDA Grand Forks Human Nutrition Research Center

Brief Summary

Moderate exercise is thought to be one of the best known means to improve how insulin works in people. Taking vitamin C and vitamin E is also thought to have the same effect. This study is being done to see if taking vitamin C and vitamin E improves or hinders how insulin works when people do not exercise and when they do exercise.

Detailed Description

The objective of the study is to determine in humans whether anti-oxidant supplementation with ascorbate (vitamin C) or R,R,R-α-tocopherol acetate (vitamin E) improves insulin sensitivity in the untrained state but blocks exercise-induced increases in insulin sensitivity and other adaptations to exercise. The results will provide new information on the roles of anti-oxidant supplementation in modifying insulin sensitivity, and will inform guidelines for anti-oxidant supplementation as an adjunct to exercise.

Study Timeline

• Study Start: 2011-05
• Study First Submitted: 2011-06-06
• Study First Submitted QC: 2011-06-07
• Study First Posted: 2011-06-08
• Primary Completion: 2012-03
• Study Completion: 2012-03
• Status Verified: 2015-03
• Last Update Submitted: 2015-03-06
• Last Update Posted: 2015-03-09

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 1

Inclusion Criteria

• 30 to 50 years of age
• Willing to not change eating habits
• Willing to not change physical activity habits
• Willing to complete the 28 week study
• Able to swallow pills

Exclusion Criteria

• smoke or use tobacco or nicotine in any form including snuff, pills, and patches
• take any medication that makes you unable to do hard exercise
• have cardiovascular, pulmonary, and/or a metabolic disease such as diabetes
• have uncontrolled high blood pressure
• have alcohol, anabolic steroids, or other substance abuse issues
• consume more than 3 alcoholic drinks/week
• have any joint or muscle injuries that affects your ability to exercise
• have cancer (other than skin cancer or carcinoma in situ of the cervix)
• are pregnant or nursing

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
(1) Blood glucose and insulin following glucose challenge in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo.	28 weeks	Individuals will be in placebo and vitamin supplemented groups in a cross-over design. A total of 6 oral glucose tolerance tests will be performed per subject in the study.

Secondary Outcome Measures

Name	Time	Method
(1) Resting metabolic rate, body composition, plasma oxidative stress, plasma vitamin E and vitamin C levels in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo.	28 weeks
(2) Fitness measures (heart rate, exercise work, VO2, VCO2, blood lactate) in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo.	28 weeks

Trial Locations

Locations (1)

Grand Forks Human Nutrition Research Center; 🇺🇸 Grand Forks, North Dakota, United States