Ignite Creation Date:
2024-05-05 @ 9:57 AM
Last Modification Date:
2024-10-26 @ 9:02 AM
Study NCT ID:
NCT00001309
Status:
COMPLETED
Last Update Posted:
2024-07-12
First Post:
1999-11-03
Brief Title:
The Bodys Affect on Vitamin C
Sponsor:
National Institute of Diabetes and Digestive and Kidney Diseases NIDDK
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Pharmacokinetics and Biodistribution of Ascorbic Acid in Healthy Human Subjects
Status:
COMPLETED
Status Verified Date:
2024-03-21
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
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
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
Detailed Description:
Vitamin C ascorbic acid ascorbate is an essential water soluble vitamin Our studies at NIH were the first to demonstrate in healthy men and women how changes in a vitamin concentration in human plasma vary as a direct function of the amount ingested over a wide range ln the present study we plan to achieve a prescorbutic vitamin C plasma concentration of approximately 5-10 micromolar in healthy human volunteers We will gradually replete these subjects with incremental doses of vitamin C to measure how their plasma red blood cell and leukocyte concentrations will change as a function of the dose We will also determine whether changes in vitamin C concentration result in changes in gene expression and metabolic profiles metabolomics lipidomics proteomics
Outpatient subjects will be encouraged to consume vitamin C in foods As inpatients vitamin C deficiency will be induced by placing subjects on a tightly restricted scorbutic diet Plasma vitamin C will be monitored several times per week When subjects have achieved a plasma ascorbate concentration of 5-10 micromolar blood sampling and urine collection over 24 hours will be performed After platelets and leukocytes are collected ascorbate repletion will begin Escalating doses of ascorbate will be administered orally and intravenously for the remainder of their inpatient admission Total daily doses of 30mg 60mg 100mg 200mg 400mg 1000mg and 2500mg will be given in two divided doses Bioavailability of ascorbate will be determined at each dosage increment When plasma ascorbate concentration reaches steady state for each dose subjects will undergo 36 hr plasma sampling and a timed 48 hr urine collection At steady state of each of 4 to 5 doses an apheresis procedure will be performed for collection of platelets and leukocytes lt is anticipated subjects will be discharged in healthy condition after 20-26 weeks
Outpatient subjects will be encouraged to consume vitamin C in foods As inpatients vitamin C deficiency will be induced by placing subjects on a tightly restricted scorbutic diet Plasma vitamin C will be monitored several times per week When subjects have achieved a plasma ascorbate concentration of 5-10 micromolar blood sampling and urine collection over 24 hours will be performed After platelets and leukocytes are collected ascorbate repletion will begin Escalating doses of ascorbate will be administered orally and intravenously for the remainder of their inpatient admission Total daily doses of 30mg 60mg 100mg 200mg 400mg 1000mg and 2500mg will be given in two divided doses Bioavailability of ascorbate will be determined at each dosage increment When plasma ascorbate concentration reaches steady state for each dose subjects will undergo 36 hr plasma sampling and a timed 48 hr urine collection At steady state of each of 4 to 5 doses an apheresis procedure will be performed for collection of platelets and leukocytes lt is anticipated subjects will be discharged in healthy condition after 20-26 weeks
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 92-DK-0033 | None | None | None |