Recruiting

Vitamin C

Sponsor:

Ohio State University

Code:

NCT07151105

Conditions

Adequate Vitamin C Status

Inadequate Vitamin C Status

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Not accepted

Interventions

Vitamin C Supplement + Low Vitamin C Diet

Placebo + Low Vitamin C Diet

Study Details

Brief summary:

This study is testing whether taking vitamin C every day can help improve gut health and reduce inflammation in adults with obesity. Poor gut health-sometimes called "leaky gut"-can allow harmful substances from bacteria to enter the bloodstream, which may lead to inflammation and increase the risk of heart disease and liver problems.

Participants will complete two study periods, each lasting two weeks, with a two-week break in between. In one period, they will take vitamin C; in the other, a placebo. During each period, researchers will collect blood, urine, and stool samples, ask participants to track their diet and activity, and perform a test to measure gut permeability.

There are minimal risks, such as discomfort from blood draws or temporary stomach upset from a sugar drink. While participants may not directly benefit, their involvement will help researchers learn whether vitamin C is a safe and effective way to improve gut health in people with obesity.

Conditions

Adequate Vitamin C Status

Inadequate Vitamin C Status

Study ID

NCT07151105

Start date

Oct 1, 2025

Status verified date

Aug, 2026

Completion date

Dec 30, 2028

Anticipated

Primary completion date

Dec 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • English speaking
  • Men and women between 18-50 years of age
  • BMI 30-40 kg/m²
  • Resting blood pressure <140/90 mm Hg
  • No use of multivitamin/vitamin C supplement within past 1-month
  • Non-vegetarian/non-vegan
  • Willingness to follow a diet low in fruits and vegetables for two, 2-week periods

Exclusion Criteria:

  • Current smoker or vaper, including tobacco, cannabis, or nicotine products
  • Alcohol consumption >2 drinks/day
  • Use of antibiotics within past 1-month
  • Use of probiotic supplements within past 1-month
  • Use of anti-inflammatory drugs within past 1-month
  • Individuals with unmanaged or poorly controlled diabetes, dyslipidemia, hypertension
  • Known history of bleeding disorders, hemochromatosis, or kidney stones
  • For Women: Pregnancy, lactation, or change in birth control within the past 3-months
  • Use of certain medications that may interact with vitamin C, including blood thinners, some antiviral drugs (e.g., indinavir), and certain antipsychotic medications (e.g., fluphenazine).

Study Design

Enrollment

34 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

placebo comparator: Inadequate Vitamin C Status

Placebo + Low Vitamin C Diet

experimental: Adequate Vitamin C Status

Vitamin C Supplement + Low Vitamin C Diet

Interventions

Vitamin C Supplement + Low Vitamin C Diet

Participants will receive a vitamin C supplement (1000 mg/d) while following a low vitamin C diet to achieve adequate vitamin C status in a blinded manner. This will be compared to participants receiving a placebo while following a low vitamin C diet that is expected to maintain inadequate vitamin C status.

Placebo + Low Vitamin C Diet

Participants will receive a placebo while following a low vitamin C diet to achieve inadequate vitamin C status in a blinded manner. This will be compared to participants receiving a vitamin C supplement while following a low vitamin C diet that is expected to maintain adequate vitamin C status.

Primary outcome measure

  • Small Intestinal Permeability [ Time Frame: Between-treatment arm comparison on day 14 following 2-week intervention. ]

Central Contacts and Locations

Central contacts

Study Coordinator

614-292-4751NutritionClinicalTrials@osu.edu

Locations

The Ohio State University

Recruiting

Columbus, Ohio, United States, 43210

More Information

Sponsor

Ohio State University

Last update posted

Sep 1, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Ohio State University on 2026-09-01.