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ClinicalTrials.gov public records Last synced Sep 14, 2026, 3:46 AM EDT

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Showing 25–48 of 24 matching trials from the live ClinicalTrials.gov search.
Local D1 index available.
Conditions
COVID-19, Coronavirus Infection, Sars-CoV2, Corona Virus Infection, COVID, Coronavirus, Coronavirus-19, Coronavirus 19
Interventions
Hydroxychloroquine, Vitamin C, Vitamin D, Zinc
Drug · Dietary Supplement
Lead sponsor
ProgenaBiome
Other
Eligibility
18 Years and older
Enrollment
254 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2020 – 2024
U.S. locations
1
States / cities
Ventura, California
Conditions
COVID, Covid-19, Corona Virus Infection, Coronavirus Infection, Coronavirus-19, SARS-CoV2, SARS-CoV Infection
Interventions
Ivermectin, Doxycycline Hcl, Zinc, Vitamin D3, Vitamin C
Drug · Dietary Supplement
Lead sponsor
ProgenaBiome
Other
Eligibility
18 Years and older
Enrollment
31 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2020 – 2022
U.S. locations
1
States / cities
Ventura, California
Conditions
Arteriovenous Fistula Occlusion
Interventions
Placebo, Ascorbic Acid, Cuprimine Oral Product
Drug
Lead sponsor
Southeast Renal Research Institute
Other
Eligibility
18 Years to 90 Years
Enrollment
30 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2017 – 2018
U.S. locations
1
States / cities
Chattanooga, Tennessee
Conditions
Venous Thromboembolism, Metastatic Pancreatic Cancer, Locally Advanced Pancreatic Adenocarcinoma
Interventions
Kinisoquin™, Placebo
Drug
Lead sponsor
Quercis Pharma AG
Industry
Eligibility
18 Years and older
Enrollment
480 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2025 – 2029
U.S. locations
3
States / cities
Ventura, California • Miami Lakes, Florida • Boston, Massachusetts
Recruiting Not applicable Interventional Accepts healthy volunteers

Impact of Phenylalanine Elevations on Brain and Cognition in Adult PKU Carriers

NCT07220265
Conditions
Carrier of Phenylketonuria, Healthy
Interventions
Phenylalanine (Phe), Placebo
Dietary Supplement
Lead sponsor
University of Missouri-Columbia
Other
Eligibility
18 Years to 60 Years
Enrollment
36 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2025 – 2026
U.S. locations
1
States / cities
Columbia, Missouri
Not listed Not applicable Interventional Accepts healthy volunteers

Antioxidant Bioavailability

NCT04463030
Conditions
Pharmacokinetics
Interventions
Liposomal vitamin C, 1 gram, Liposomal vitamin C, 2 grams, Liposomal vitamin C, 5 grams, Placebo
Dietary Supplement
Lead sponsor
Natural Immune Systems Inc
Other
Eligibility
18 Years to 70 Years
Enrollment
24 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2020 – 2023
U.S. locations
1
States / cities
Klamath Falls, Oregon
Conditions
Stroke, Ischemic Stroke, Cerebrovascular Accident
Interventions
Beet it Beetroot juice, Beet It Placebo Beetroot juice
Drug
Lead sponsor
Wake Forest University Health Sciences
Other
Eligibility
18 Years and older
Enrollment
18 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2012 – 2016
U.S. locations
1
States / cities
Winston-Salem, North Carolina
Completed Not applicable Interventional Accepts healthy volunteers Results available

Ischemia/Reperfusion Injury of Human Endothelium: Role of Glucose and Statins

NCT00995670
Conditions
Hyperglycemia
Interventions
5% dextrose, Vitamin C, Simvastatin, Sevoflurane
Drug
Lead sponsor
US Department of Veterans Affairs
Federal
Eligibility
18 Years to 35 Years
Enrollment
59 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2010 – 2013
U.S. locations
1
States / cities
Milwaukee, Wisconsin
Completed Early Phase 1 Interventional

Exercise and NO in HFrEF

NCT03136029
Conditions
Heart Failure With Reduced Ejection Fraction
Interventions
Antioxidant, Tetrahydrobiopterin (BH4), Exercise training
Dietary Supplement · Other
Lead sponsor
VA Office of Research and Development
Federal
Eligibility
18 Years and older
Enrollment
68 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2018 – 2025
U.S. locations
1
States / cities
Salt Lake City, Utah
Completed Not applicable Interventional Accepts healthy volunteers Results available

Cervical Preparation Before Dilation and Evacuation

NCT01751087
Conditions
Abortion, Induced
Interventions
Mifepristone, misoprostol, Osmotic dilators, placebo
Other · Drug · Device
Lead sponsor
Planned Parenthood League of Massachusetts
Other
Eligibility
18 Years and older · Female only
Enrollment
300 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2013 – 2014
U.S. locations
7
States / cities
San Francisco, California • Chicago, Illinois • Boston, Massachusetts + 3 more
Terminated Not applicable Interventional Accepts healthy volunteers

The Effects of Vitamin C on Acute-Exercise in Postmenopausal Females

NCT07109115
Conditions
Females, Males, Menopause, Sedentary, Healthy Participants
Interventions
Vitamin C (Ascorbic Acid)
Dietary Supplement
Lead sponsor
University of Virginia
Other
Eligibility
45 Years and older
Enrollment
1 participant
Healthy volunteers
Accepts healthy volunteers
Timeline
2025 – 2026
U.S. locations
1
States / cities
Charlottesville, Virginia
Completed Not applicable Interventional Accepts healthy volunteers

Nutrition Interventions to Support the Immune System in Response to Stress

NCT02053506
Conditions
Mitigation of Immune Function Decrements in Response to Stress
Interventions
Immune-enhancing nutritional beverage, Probiotics (BB-12), Placebo (for nutritional beverage and probiotic)
Dietary Supplement
Lead sponsor
United States Army Research Institute of Environmental Medicine
Federal
Eligibility
18 Years to 45 Years
Enrollment
63 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2014 – 2016
U.S. locations
1
States / cities
Natick, Massachusetts
Conditions
Excessive Physical Exercise, Unspecified
Interventions
Arginine antioxidant supplements, Placebo
Dietary Supplement
Lead sponsor
University of California, Los Angeles
Other
Eligibility
50 Years to 75 Years
Enrollment
16 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2004 – 2005
U.S. locations
1
States / cities
Los Angeles, California
Conditions
Lumbar Spine Surgery
Interventions
Vitamin C, Placebo
Dietary Supplement
Lead sponsor
University of Kansas Medical Center
Other
Eligibility
45 Years to 80 Years
Enrollment
55 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2019 – 2022
U.S. locations
1
States / cities
Kansas City, Kansas
Completed Not applicable Interventional Accepts healthy volunteers

Racial and Aging Effects of Acute Antioxidant Supplementation

NCT02157207
Conditions
Healthy
Interventions
Antioxidant, Placebo
Dietary Supplement · Other
Lead sponsor
University of Illinois at Chicago
Other
Eligibility
18 Years to 75 Years
Enrollment
93 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2014 – 2015
U.S. locations
1
States / cities
Chicago, Illinois
Completed Phase 1 Interventional Accepts healthy volunteers

Safety and Immunogenicity of Peru-15-pCTB in Healthy Adult Subjects

NCT00654108
Conditions
Gastroenteritis Escherichia Coli
Interventions
Ciprofloxacin, Peru-15-pCTB, Sodium bicarbonate/Ascorbic Acid/Aspartame Buffer
Drug · Biological · Other
Lead sponsor
National Institute of Allergy and Infectious Diseases (NIAID)
NIH
Eligibility
18 Years to 45 Years
Enrollment
62 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2008 – 2010
U.S. locations
1
States / cities
Cincinnati, Ohio
Not yet recruiting Not applicable Interventional Accepts healthy volunteers

The Impact of Qualia Vitamin C+ on Individuals With Suboptimal and Adequate Vitamin C Levels

NCT07652346
Conditions
Healthy, Suboptimal Vitamin C Levels, Adequate Vitamin C Levels
Interventions
Qualia Vitamin C+, Placebo
Dietary Supplement · Other
Lead sponsor
Qualia Life Sciences
Industry
Eligibility
25 Years to 75 Years
Enrollment
152 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2026
U.S. locations
1
States / cities
Carlsbad, California
Conditions
Safety, Tolerance
Interventions
Crystal Light (once serving), Liquid IV with amino acids (one serving), Liquid IV with amino acids (two servings), Liquid IV with amino acids (three servings)
Dietary Supplement
Lead sponsor
University of Memphis
Other
Eligibility
18 Years to 50 Years
Enrollment
40 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2022 – 2023
U.S. locations
1
States / cities
Memphis, Tennessee
Conditions
Glutathione-cyclodextrin Complex Absorption
Interventions
Glutaryl Solution, Placebo Solution
Dietary Supplement
Lead sponsor
Western University of Health Sciences
Other
Eligibility
21 Years to 65 Years
Enrollment
30 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2022
U.S. locations
1
States / cities
Pomona, California
Completed Not applicable Interventional Accepts healthy volunteers

The Effect of Melatonin and Vitamin C on COVID-19

NCT04530539
Conditions
Covid19, SARS-CoV Infection
Interventions
Vitamin C, melatonin, Placebo, Symptom Survey
Dietary Supplement · Other
Lead sponsor
Lancaster General Hospital
Other
Eligibility
50 Years and older
Enrollment
122 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2020 – 2022
U.S. locations
1
States / cities
Lancaster, Pennsylvania
Terminated Early Phase 1 Interventional Accepts healthy volunteers

Targeting ER Stress in Vascular Dysfunction

NCT04001647
Conditions
Vasodilation, Arterial Stiffness
Interventions
Acetylcholine, Sodium Nitroprusside, Ascorbic Acid
Drug
Lead sponsor
Colorado State University
Other
Eligibility
18 Years to 80 Years
Enrollment
17 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2019 – 2022
U.S. locations
1
States / cities
Fort Collins, Colorado
Completed Not applicable Interventional Accepts healthy volunteers

Nitrate and Vitamin C on Vascular Health Oxidative Stress

NCT04283630
Conditions
Endothelial Dysfunction
Interventions
Dietary nitrate in the form of beetroot juice for all participnats, Nature Made vitamin c 1000 mg, Placebo
Dietary Supplement
Lead sponsor
David Travis Thomas
Other
Eligibility
50 Years to 70 Years
Enrollment
23 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2018 – 2019
U.S. locations
2
States / cities
Lexington, Kentucky
Completed Early Phase 1 Interventional Accepts healthy volunteers

Local Vasoconstriction in Postural Tachycardia Syndrome

NCT01210430
Conditions
Postural Tachycardia Syndrome
Interventions
Losartan, Ascorbic Acid (Vitamin C), Normal Saline
Drug
Lead sponsor
New York Medical College
Other
Eligibility
14 Years to 29 Years
Enrollment
74 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2010 – 2015
U.S. locations
1
States / cities
Hawthorne, New York
Conditions
Photodamaged Skin
Interventions
Vitamin C with AHA Exfoliative Serum, Placebo serum
Drug
Lead sponsor
Austin Institute for Clinical Research
Network
Eligibility
30 Years to 65 Years · Female only
Enrollment
34 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2023 – 2024
U.S. locations
1
States / cities
Pflugerville, Texas