Vitamin A StatusPhase 1NCT00636038
Bioavailability of Yellow Maize Carotenoids in Humans
A Phase 1 study testing corn beta-carotene in people with Vitamin A Status, run by Tufts University at 1 site in Zimbabwe.
Trial summary
The study hypothesis is that high ß-C yellow maize can provide vitamin A efficiently. list item one ß-C in yellow maize The study will use stable isotope labeled high ß-C yellow maize and vitamin A in a well-nourished population by utilizing stable isotope dilution techniques. Read more about this study
- Who is it for?
- Ages 40 to 70 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Vitamin A Status
- What is being tested?
- corn beta-carotene
- How many people
- 8 participants
- Where
- 1 siteZimbabwe
- Study dates
- Jan 2008to Mar 2008
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 70 years
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- healthy subjects
Who cannot join
- GI track problems
Trial locations and contacts
1 site in 1 country.
About this study
The study hypothesis is that high ß-C yellow maize can provide vitamin A efficiently.
- list item one ß-C in yellow maize
Read more
The study will use stable isotope labeled high ß-C yellow maize and vitamin A in a well-nourished population by utilizing stable isotope dilution techniques. In this project, deuterium labeled vitamin A that is derived from the labeled ß-C yellow maize will be traced after being eaten by a human subject. Eight men (> 40 years and < 70 y) who are healthy, non-smoking,body weight within 20% of standard weight for height (Metropolitan) and not having taken vitamin A or ß-C supplements within the last month will be recruited as volunteers. This study will last for 50 days during which at day 1, cooked labeled yellow maize paste (porridge) equal to a total of ~ 2 bowls cooked yellow maize (from 100 - 200 g dry weight) containing ~ 1 mg ß-C will be taken by each volunteer. On day 8, a labeled vitamin A (1 mg of 13C retinyl acetate) in oil dose will be used in evaluation of liver storage of vitamin A. Forty six blood samples (460 cc) will be taken during the study which will be analyzed for serum carotenoids and retinoids using HPLC and mass spectrometry techniques.
The serum concentration and isotope ratio of ß-C and retinol will be determined. Serum enrichment curve following each oral dose will be studied. The area under the curve (AUC) of retinol-d4 and labeled retinol from the reference dose in serum samples will be determined and compared. The equivalence of a high ß-C corn meal to vitamin A will be calculated based on the isotope reference method to determine the efficiency of corn ß-C to provide vitamin A.
Read the detailed description
- list item one ß-C in yellow maize
Pro-vitamin A carotenoids in plants are a major and safe vitamin A source for a vast population in the world. Even though, ß-carotene (ß-C) in vegetables has been considered as a safe vitamin A source, it is essential to determine the efficiency of provitamin A carotenoids in plant conversion to vitamin A. However, the bioavailability of vitamin A and carotenoids from food matrices has not been well studied due to the unavailability of isotopically labeled foods that can be fed to humans.
The main objective of this study is to investigate the bioavailability of ß-C in yellow maize and its bioconversion to retinol stored in the liver using stable isotope labeled high ß-C yellow maize and vitamin A in a well-nourished population by utilizing stable isotope dilution techniques. In this project, the deuterium labeled vitamin A that is derived from the labeled ß-C yellow maize will be traced after being eaten by a human subject. This will allow for quantitative determination of the vitamin A equivalence of high ß-C plant foods.
Eight men (> 40 years and < 70 y) who are healthy, non-smoking adults must have their body weight within 20% of standard weight for height (Metropolitan) and not having taken vitamin A or ß-C supplements within the last month will be recruited as volunteers.
This is a 50 day study during which dose 1, cooked labeled yellow maize paste (porridge) equal to a total of ~ 2 bowls cooked yellow maize (from 100 - 200 g dry weight) containing ~ 1 mg ß-C will be taken by each volunteer. On day 8, dose 2 will be used in evaluation of liver storage of vitamin A using 1 mg of 13C retinyl acetate. One blood sample (20 cc) will be drawn during the screening process. Forty six blood samples (460 cc) will be taken during the study which will be analyzed for serum carotenoids and retinoids using HPLC and mass spectrometry techniques. The serum concentration and isotope ratio of ß-C and retinol will be determined. Serum enrichment curve following each oral dose will be studied. The area under the curve (AUC) of retinol-d4 and labeled retinol from the reference dose in serum samples will be determined and compared. The equivalence of a high ß-C plant food supplement to a vitamin A dose will be calculated based on the isotope reference method.
- Conditions
- Vitamin A Status
- Being tested
- corn beta-carotene
- Keywords
- beta-carotene, yellow maize, vitamin A
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
corn beta-caroteneDietary supplement
Also called staple food beta-carotene
yellow corn beta-carotene in a 1 mg level to be taken as corn porridge in one meal by volunteers
What is being measured
The primary outcome is the main question the study is designed to answer.
Bioavailability of corn beta-carotene and its equivalency to provide vitamin A
Measured: one year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Mar 2008 (estimated)
- Study startJan 2008
- Primary completionMar 2008
- Study completionMar 2008
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Vitamin A StatusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tufts University
- Sponsor type
- University, hospital or other
- Collaborators
- Nutricia Research Fundation, National University of Science and Technology, Zimbabwe
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00636038
- Sponsor's protocol ID
- 2007-E6
- Status last verified
- Mar 2008
- First submitted
- 7 Mar 2008
- Last updated
- 14 Mar 2008
- Results posted
- No
- Data monitoring committee
- No
Publications
Muzhingi T, Gadaga TH, Siwela AH, Grusak MA, Russell RM, Tang G. Yellow maize with high beta-carotene is an effective source of vitamin A in healthy Zimbabwean men. Am J Clin Nutr. 2011 Aug;94(2):510-9. doi: 10.3945/ajcn.110.006486. Epub 2011 Jun 29.
PubMed 21715509
Study at a glance
From the registry record, last updated by the sponsor on 14 Mar 2008. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Bioavailability of Yellow Maize Carotenoids in Humans
- ClinicalTrials.gov ID
- NCT00636038
- Acronym / sponsor ID
- 2007-E6
- Conditions
- Vitamin A Status
- Keywords
- beta-carotene, yellow maize, vitamin A
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 8 participants (actual)
- Lead sponsor
- Tufts UniversityUniversity, hospital or other
- Collaborators
- Nutricia Research Fundation, National University of Science and Technology, Zimbabwe
- Study start
- Jan 2008
- Primary completion
- Mar 2008 (actual)
- Study completion
- Mar 2008 (actual)
- First posted
- 14 Mar 2008 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study hypothesis is that high ß-C yellow maize can provide vitamin A efficiently.
- list item one ß-C in yellow maize
The study will use stable isotope labeled high ß-C yellow maize and vitamin A in a well-nourished population by utilizing stable isotope dilution techniques. In this project, deuterium labeled vitamin A that is derived from the labeled ß-C yellow maize will be traced after being eaten by a human subject. Eight men (> 40 years and < 70 y) who are healthy, non-smoking,body weight within 20% of standard weight for height (Metropolitan) and not having taken vitamin A or ß-C supplements within the last month will be recruited as volunteers. This study will last for 50 days during which at day 1, cooked labeled yellow maize paste (porridge) equal to a total of ~ 2 bowls cooked yellow maize (from 100 - 200 g dry weight) containing ~ 1 mg ß-C will be taken by each volunteer. On day 8, a labeled vitamin A (1 mg of 13C retinyl acetate) in oil dose will be used in evaluation of liver storage of vitamin A. Forty six blood samples (460 cc) will be taken during the study which will be analyzed for serum carotenoids and retinoids using HPLC and mass spectrometry techniques.
The serum concentration and isotope ratio of ß-C and retinol will be determined. Serum enrichment curve following each oral dose will be studied. The area under the curve (AUC) of retinol-d4 and labeled retinol from the reference dose in serum samples will be determined and compared. The equivalence of a high ß-C corn meal to vitamin A will be calculated based on the isotope reference method to determine the efficiency of corn ß-C to provide vitamin A.
Detailed description
- list item one ß-C in yellow maize
Pro-vitamin A carotenoids in plants are a major and safe vitamin A source for a vast population in the world. Even though, ß-carotene (ß-C) in vegetables has been considered as a safe vitamin A source, it is essential to determine the efficiency of provitamin A carotenoids in plant conversion to vitamin A. However, the bioavailability of vitamin A and carotenoids from food matrices has not been well studied due to the unavailability of isotopically labeled foods that can be fed to humans.
The main objective of this study is to investigate the bioavailability of ß-C in yellow maize and its bioconversion to retinol stored in the liver using stable isotope labeled high ß-C yellow maize and vitamin A in a well-nourished population by utilizing stable isotope dilution techniques. In this project, the deuterium labeled vitamin A that is derived from the labeled ß-C yellow maize will be traced after being eaten by a human subject. This will allow for quantitative determination of the vitamin A equivalence of high ß-C plant foods.
Eight men (> 40 years and < 70 y) who are healthy, non-smoking adults must have their body weight within 20% of standard weight for height (Metropolitan) and not having taken vitamin A or ß-C supplements within the last month will be recruited as volunteers.
This is a 50 day study during which dose 1, cooked labeled yellow maize paste (porridge) equal to a total of ~ 2 bowls cooked yellow maize (from 100 - 200 g dry weight) containing ~ 1 mg ß-C will be taken by each volunteer. On day 8, dose 2 will be used in evaluation of liver storage of vitamin A using 1 mg of 13C retinyl acetate. One blood sample (20 cc) will be drawn during the screening process. Forty six blood samples (460 cc) will be taken during the study which will be analyzed for serum carotenoids and retinoids using HPLC and mass spectrometry techniques. The serum concentration and isotope ratio of ß-C and retinol will be determined. Serum enrichment curve following each oral dose will be studied. The area under the curve (AUC) of retinol-d4 and labeled retinol from the reference dose in serum samples will be determined and compared. The equivalence of a high ß-C plant food supplement to a vitamin A dose will be calculated based on the isotope reference method.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
Who may qualify
- Ages
- 40 to 70 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- healthy subjects
Key exclusion criteria (1 listed)
- GI track problems
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| corn beta-caroteneAlso: staple food beta-caroteneyellow corn beta-carotene in a 1 mg level to be taken as corn porridge in one meal by volunteers | Dietary supplement | – |
Primary outcome
Bioavailability of corn beta-carotene and its equivalency to provide vitamin A
Time frame: one year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Mar 2008.
- Derived from this study: PubMed 21715509Muzhingi T, Gadaga TH, Siwela AH, Grusak MA, Russell RM, Tang G. Yellow maize with high beta-carotene is an effective source of vitamin A in healthy Zimbabwean men. Am J Clin Nutr. 2011 Aug;94(2):510-9. doi: 10.3945/ajcn.110.006486. Epub 2011 Jun 29.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing corn beta-carotene in people with Vitamin A Status, run by Tufts University at 1 site in Zimbabwe.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Mar 2008. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Zimbabwe. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Bioavailability of corn beta-carotene and its equivalency to provide vitamin A (time frame: one year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00636038, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Mar 2008.