NIH Clinical Center Search the Studies: Study Number, Study Title

Protocol Details

Pharmacokinetics and Biodistribution of Ascorbic Acid in Healthy Human Subjects

This study is NOT currently recruiting participants.

Summary | Eligibility | Citations | Contacts

Summary

Number

92-DK-0033

Sponsoring Institute

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Completed Study; data analyses ongoing
Gender: Male & Female
Min Age: 18
Max Age: 35

Referral Letter Required

No

Population Exclusion(s)

Children

Special Instructions

Currently Not Provided

Keywords

Pharmacokinetics;
Biodistribution;
Ascorbic Acid

Recruitment Keyword(s)

None

Condition(s)

Healthy Volunteers

Investigational Drug(s)

None

Investigational Device(s)

None

Intervention(s)

Other: Vitamin C

Supporting Site

National Institute of Diabetes and Digestive and Kidney Diseases

Pharmacokinetics is the term used for how the body affects a drug once it is taken. Vitamin C, also known as ascorbic acid, is an essential water soluble vitamin. Meaning, the body does not make Vitamin C it must be taken in through the diet. In this study researchers will attempt to determine how the amount of water consumed affects the level of vitamin C in the blood (specifically the plasma component of the blood).

In this study researchers will take 13 subjects and place them on a Vitamin C restricted diet. Vitamin C levels will be measured twice a week on an outpatient basis until all subjects reach a desired low level of Vitamin C (12-15 micromolar plasma ascorbic acid concentration). Subjects will then be admitted and undergo 24 hour blood and urine collection. Following the collection of samples, subjects will then begin to receive Vitamin C orally (by mouth) and intravenously (injected into the vein). The dosage of Vitamin C will gradually increase from 30 mg-2500 mg divided into two daily doses. Blood and urine samples will be collected each time the dose is increased. The study will take approximately 18 weeks after which the subjects will be discharged in healthy condition.

--Back to Top--

Eligibility

INCLUSION CRITERIA:

-10 Males - ages 18 - 35 yrs

-10 Females - ages 18 - 35 yrs

No more than 4 subjects during any period will remain as inpatients on the endocrine/metabolic ward. These subjects will be normal volunteers selected from colleges/universities who will:

a. Spend within a fall or spring semester (approximately 20-26 weeks) as an inpatient resident on the endocrine-metabolic ward at NIH.

b. Be willing to adhere to an ascorbate restricted diet for the duration of the time spent in the study as an inpatient at NlH.

c. Have veins adequate for venipunctures and be willing to undergo venipunctures approximately two to three times per week.

d. Refrain from ingestion of any medication and cigarette smoking and ethanol.

e. Be able to give informed consent.

EXCLUSION CRITERIA:

a. Subject non-compliance with restricted diet.

b. Pregnancy as determined by history, physical exam and urine b-HCG.

c. History of diabetes mellitus, bleeding disorders, kidney stones, glucose-6- phosphate dehydrogenase deficiency, family history of hemochromatosis/iron overload.

d. Platelet count <150,000/ul blood; prothrombin time/partial thromboplastin time (PT/PTT) > 1 second above normal upper limit.

e. Positive test for exposure to human immunodeficiency virus.

f. Positive tests for hepatitis B surface antigen, core antibody or surface antibody.


--Back to Top--

Citations:

Not Provided

--Back to Top--

Contacts:

Principal Investigator

Referral Contact

For more information:

Mark A. Levine, M.D.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
BG 10 RM 4D52
10 CENTER DR
BETHESDA MD 20814
(301) 402-5588
markl@mail.nih.gov

Mark A. Levine, M.D.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
BG 10 RM 4D52
10 CENTER DR
BETHESDA MD 20814
(301) 402-5588
markl@mail.nih.gov

Office of Patient Recruitment
National Institutes of Health Clinical Center (CC)
Building 61, 10 Cloister Court
Bethesda, Maryland 20892
Toll Free: 1-800-411-1222
Local Phone: 301-451-4383
TTY: 1-866-411-1010
PRPL@cc.nih.gov

Clinical Trials Number:

NCT00001309

--Back to Top--