Comparative Bioavailability of Two Forms of Vitamin C

A Randomized, Double-blind, Placebo-controlled Crossover Study Comparing the Bioavailability of Two Forms of Vitamin C in Plasma and Leukocytes Over 24 Hours.

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01852903

Enrollment

Registered

2013-05-14

Start date

2011-05-31

Completion date

Unknown

Last updated

2013-05-14

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

Conditions

Bioavailability

Keywords

vitamin C, calcium ascorbate, ascorbic acid, bioavailability

Brief summary

The purpose of this study is to compare levels of vitamin C in the blood over the 24 hour period following a single 1000 mg dose of vitamin C from ascorbic acid, calcium ascorbate and placebo.

Interventions

DIETARY_SUPPLEMENTcalcium ascorbate

DIETARY_SUPPLEMENTascorbic acid

OTHERplacebo

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 60 Years

Inclusion criteria

* Healthy as determined by laboratory results and medical history * Females not of child bearing potential * BMI 18-30 kg/m2 * Agrees to consume a low vitamin C diet * Non-smoker or ex-smoker \>1 year

Exclusion criteria

* Pregnant, breastfeeding, or planning to become pregnant during the trial * Alcohol \>2 drinks per day; alcohol or drug abuse within the past year * Cardiac conditions * Duodenal ulcer or gastric ulcer, gastritis, hiatus hernia, or gastroesophageal reflux disease (GERD) within past 3 months * History irritable bowel syndrome, malabsorption or significant GI disease * History of kidney stones * Use of medications known to interact with vitamin C * Use of supplements containing vitamin C * Use of anticoagulants (warfarin), barbiturates, tetracycline antibiotics, beta-blockers, cyclosporine, prednisone, tricyclic antidepressants, diuretics and nitrate medications * History of or current diagnosis of cancer * Uncontrolled hypertension * History of diabetes, renal disease and/or liver disease * Unstable psychiatric disorder * History of or current immunocompromise * History of hemochromatosis or hemoglobinopathies * Participation in a clinical research trial \<30 days * Use of acute medication w/in 72 hours of intervention * Unstable medications \<90 days * Abnormal liver function * Serum creatinine \> 1.5 x upper limit of normal (ULN) * Anemia of any etiology * Blood donation w/in the last 2 months * Allergy or sensitivity to test articles, foods or beverages provided during the study * Cognitive impairment and/or unable to give informed consent

Design outcomes

Primary

Measure	Time frame
Plasma and leukocyte vitamin C concentration	0, 2, 4, 8 and 24 hours

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 1, 2026