CClinicalTrials.gg
CompletedNCT03562988Updated Aug 23, 2021Results posted

Bioequivalence Study on Vitamin C in Healthy Adults

An interventional study of Vitamin C gummy and Vitamin C tablet in Dietary Exposure, sponsored by Church & Dwight Company, Inc.. Completed at 1 site in United States. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-08-23.

Sponsored by Church & Dwight Company, Inc. · Not applicable, Interventional, and Other

From the registry’s dates

  • Registered 9 months after the study started (first participant enrolled Aug 2017, registered May 2018).
Phase
Not applicable
Study type
Interventional
Enrollment
35
Allocation
Randomized
Ages
18 Years to 55 Years
Sex
All
01

Study summary

The objective of this exploratory pharmacokinetic research study is to demonstrate that both caplets and gummies provide an effective dose of ascorbic acid in healthy adults.

Read the detailed description

This randomized, examiner-blind, cross-over study evaluates the bioequivalence of a gummy containing vitamin C relative to a caplet comparator product in healthy adults.

02

Conditions studied

  • Dietary Exposure

Keywords

  • Measure Absorption of Vitamin C in Blood
03

In context

Lead sponsor

Church & Dwight Company, Inc. is the lead sponsor of 33 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 55 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • BMI 18.5 to 29.9 kg/m2 (+/- 1 kg/m2)
  • Healthy as determined by laboratory results and medical history
  • Maintains current level of physical activity throughout duration of study
  • Does not donate blood for the next 3 months after completing study
  • Avoidance of foods and beverages fortified with vitamin C for at least 7 days prior to enrollment and duration of study
  • Avoidance of citrus foods, citrus juices, and tomato juice for at least 7 days prior to enrollment and duration of study
  • Non smoker or ex-smoker > 1 year
  • Has given voluntary, written informed consent to participate in study
  • Agrees to avoid high caffeine and alcohol intake 72 hours prior to in-clinic test days and during the 24-hour in-clinic test days
  • Females not of child bearing potential, defined as having had a hysterectomy, oophorectomy, bilateral tubal ligation or are post-menopausal
  • Females of child bearing potential must agree to use a medically approved method of birth control and have a negative urine pregnancy test result. Acceptable methods include hormonal contraceptives, double-barrier method, intrauterine devices, non-heterosexual lifestyle or agrees to use contraception if planning on changing to heterosexual partner(s) and/or vasectomy of partner

Exclusion criteria

Exclusion Criteria:

  • Women who are pregnant, breast feeding, or planning to become pregnant during the trial
  • Duodenal or gastric ulcer, gastritis, hiatus hernia, or GERD within past 3 months
  • History of irritable bowel syndrome and related disorders
  • Significant gastrointestinal disease (includes but not limited to Celiac disease)
  • History of malabsorption
  • Unstable medical conditions as determined by the Qualified Investigator
  • Blood pressure greater than 150/90 mmHg
  • Cancer except skin cancers completely excised with no chemotherapy or radiation following and with a negative follow up. (Volunteers with cancer in full remission for more than 4 years after diagnosis are acceptable)
  • Clinically significant abnormal laboratory results at screening
  • Metabolic disease or chronic diseases (ex/ hyperlipidemia, hypertension, hypercholesterolemia)
  • Type I or Type II diabetes
  • History of kidney stones
  • Use of prescription or over the counter products known to interact with vitamin C within 72 hours of enrollment and duration of trial such as aspirin and NSAIDs, aluminum, iron, and proton pump inhibitors
  • Use of acute over the counter medication within 72 hours of test product dosing
  • Use of tobacco products within the last year
  • More than 2 alcoholic drinks per day
  • Drug abuse within 1 year of enrollment
  • Use of medicinal marijuana
  • Immunocompromised individuals such as individuals that have undergone organ transplantation or individuals diagnosed with HIV
  • Individuals who have planned surgery during the course of the trial
  • St. John's wort in the last 30 days prior to enrollment and duration of study
  • Use of vitamin C, multivitamins containing vitamin C, or foods or beverages fortified with vitamin C and other natural healthy products containing vitamin C within 7 days of enrollment and duration of study
  • Consumption of citrus foods, citrus juices, and tomato juice with 7 days of enrollment and duration of study
  • Use of anticoagulants, barbiturates, tetracycline antibiotics, beta-blockers, cyclosporine, prednisone, tricyclic antidepressants, diuretics and nitrate medications
  • Use of natural health products/dietary supplements with 7 days of enrollment or duration of study
  • Current diagnosis and history of blood/bleeding disorders
  • Current diagnosis and history of anemia of any etiology defined as hemoglobin \< 145 g/L for males and \< 123 g/L for females
  • History of hemoglobinopathies such as sickle cell anemia or thalassemia, sideroblastic anemia
  • History of hemochromatosis
  • Blood donation in the past 3 months
  • Individuals who plan to donate blood during the study or within 30 days of completing the study
  • Participation in a clinical research trial within 30 days prior to enrollment
  • Allergy or sensitivity to supplement ingredients or to any food or beverage provided during the study
  • Individuals who are cognitively impaired and/or who are unable to give informed consent
  • Any other condition which in the Qualified Investigator's opinion nay adversely affect an individual's ability to complete the study or its measures or which may pose significant risk to the individual
05

Study design

Phase
Not applicable
Primary purpose
Other
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Investigator)
Enrollment
35 participants (actual)

Study arms

  • Other
    Vitamin C gummy, Then Vitamin C Caplet

    The study consisted of two single-day study periods separated by a 7-day washout. At the first study day, a single oral dose of vitamin C gummy (1007.2mg) was orally administered following a 12 hour fasting period. After a 7 day washout period, a single oral dose of vitamin C caplet (1027.9mg) was orally administered following a 12 hour fasting period.

    Dietary Supplement: Vitamin C gummy · Dietary Supplement: Vitamin C tablet

  • Other
    Vitamin C tablet, Then Vitamin C gummy

    The study consisted of two single-day study periods separated by a 7-day washout. At the first study day, a single oral dose of vitamin C caplet (1027.9mg) was orally administered following a 12 hour fasting period. After a 7 day washout period, a single oral dose of vitamin C gummy (1007.2mg) was orally administered following a 12 hour fasting period.

    Dietary Supplement: Vitamin C gummy · Dietary Supplement: Vitamin C tablet

Interventions

  • Dietary supplementVitamin C gummy

    vitamin C

  • Dietary supplementVitamin C tablet

    vitamin C

06

What researchers measure

Primary outcomes

  1. Mean Plasma L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]

    Mean Plasma L-ascorbic Acid as Total Area Under the Curve \[AUC(0-24 hours)\]

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

  2. Mean Leukocyte L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]

    Mean Leukocyte L-ascorbic Acid as Total Area Under the Curve \[AUC(0-24 hours)\] for All Study Participants

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

  3. Mean Plasma L-ascorbic Acid as Cmax

    Mean Plasma L-ascorbic Acid as Cmax

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

  4. Mean Leukocyte L-ascorbic Acid as Cmax

    Mean Leukocyte L-ascorbic Acid as Cmax

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

Secondary outcomes

  1. Mean Plasma Vitamin C Absorption Rate as Tmax

    Mean Time of maximum Vitamin C concentration

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

  2. Mean Leucocyte Vitamin C Absorption Rate as Tmax

    Mean Time of maximum Vitamin C concentration

    Time frame: baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours

07

Results

Posted Aug 23, 2021

Participant flow

Participant flow — Overall Study
MilestoneVitamin C Gummy, Then Vitamin C CapletVitamin C Tablet, Then Vitamin C Gummy
Started1718
Completed1515
Not completed23

Outcome measures

PrimaryMean Plasma L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]

Mean Plasma L-ascorbic Acid as Total Area Under the Curve \[AUC(0-24 hours)\]

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · μmol*min/L
Mean Plasma L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]
μmol*min/LVitamin C GummyVitamin C Caplet
Mean Plasma L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]1114.66 ± 236.811149.09 ± 237.89
PrimaryMean Leukocyte L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]

Mean Leukocyte L-ascorbic Acid as Total Area Under the Curve \[AUC(0-24 hours)\] for All Study Participants

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · nmol*min/10^8 leukocytes
Mean Leukocyte L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]
nmol*min/10^8 leukocytesVitamin C GummyVitamin C Tablet
Mean Leukocyte L-ascorbic Acid as Total Area Under the Curve [AUC(0-24 Hours)]273.20 ± 115.70297.20 ± 105.86
PrimaryMean Plasma L-ascorbic Acid as Cmax

Mean Plasma L-ascorbic Acid as Cmax

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · μmol/L
Mean Plasma L-ascorbic Acid as Cmax
μmol/LVitamin C GummyVitamin C Tablet
Mean Plasma L-ascorbic Acid as Cmax72.75 ± 15.7478.97 ± 20.51
PrimaryMean Leukocyte L-ascorbic Acid as Cmax

Mean Leukocyte L-ascorbic Acid as Cmax

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · nmol/10^8 leukocytes
Mean Leukocyte L-ascorbic Acid as Cmax
nmol/10^8 leukocytesVitamin C GummyVitamin C Tablet
Mean Leukocyte L-ascorbic Acid as Cmax22.96 ± 18.9122.74 ± 13.98
SecondaryMean Plasma Vitamin C Absorption Rate as Tmax

Mean Time of maximum Vitamin C concentration

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · hours
Mean Plasma Vitamin C Absorption Rate as Tmax
hoursVitamin C GummyVitamin C Tablet
Mean Plasma Vitamin C Absorption Rate as Tmax2.59 ± 0.712.88 ± 1.11
SecondaryMean Leucocyte Vitamin C Absorption Rate as Tmax

Mean Time of maximum Vitamin C concentration

Time frame:
baseline, 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours
Reported as:
Mean · hours
Mean Leucocyte Vitamin C Absorption Rate as Tmax
hoursVitamin C GummyVitamin C Tablet
Mean Leucocyte Vitamin C Absorption Rate as Tmax6.73 ± 3.614.58 ± 3.84

Adverse events

Collected over Participants entered any AE's in a daily diary from the initiation of the study until 24 hours after the last oral dosing. Additionally, participants were asked about AE's at each visit.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Vitamin C Gummy0/35 (0%)0/35 (0%)2/32 (6.3%)
Vitamin C Tablet0/35 (0%)0/35 (0%)1/33 (3%)
Most frequent other events
Most frequent other events
EventVitamin C GummyVitamin C Tablet
Abnormal Neutrophil CountBlood and lymphatic system disorders1/320/33
Mild SomnolenceGeneral disorders1/320/33
Mild NauseaGastrointestinal disorders0/321/33

Baseline characteristics

Cross over study. Participants randomly received one treatment at one of the two dosing days and the other treatment at the second dosing day.

Age, Categorical
Age, Categorical(Participants)All Study Participants
<=18 years0
Between 18 and 65 years35
>=65 years0
Sex: Female, Male
Sex: Female, Male(Participants)All Study Participants
Female24
Male11
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)All Study Participants
Hispanic or Latino3
Not Hispanic or Latino32
Unknown or Not Reported0
08

Study locations

1 site
  • Church & Dwight Co., Inc.
    Princeton, New Jersey 08543, United States
09

References and documents

Publications

  • Evans M, Guthrie N, Zhang HK, Hooper W, Wong A, Ghassemi A. Vitamin C Bioequivalence from Gummy and Caplet Sources in Healthy Adults: A Randomized-Controlled Trial. J Am Coll Nutr. 2020 Jul;39(5):422-431. doi: 10.1080/07315724.2019.1684398. Epub 2019 Nov 20. PubMed 31747355 ↗

Study documents

  • Protocol and statistical analysis plan · Jun 13, 2017

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 23, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT03562988
Lead sponsor
Church & Dwight Company, Inc.
Collaborators
KGK Science Inc.
Responsible party
Sponsor
First posted
Jun 20, 2018
Start date
Aug 1, 2017
Primary completion
Dec 22, 2017
Completion
Dec 22, 2017
Results posted
Aug 23, 2021
Last update
Aug 23, 2021

Study contacts

Annahita Ghassemi
study director · Church & Dwight Company, Inc.

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Apr 2021. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion