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Bioavailability of Yellow Maize Carotenoids in Humans

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ClinicalTrials.gov Identifier: NCT00636038
Recruitment Status : Completed
First Posted : March 14, 2008
Last Update Posted : March 14, 2008
Sponsor:
Collaborators:
Information provided by:

Study Description
Brief 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. 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.


Condition or disease Intervention/treatment Phase
Vitamin A Status Dietary Supplement: corn beta-carotene Phase 1

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

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 8 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Study Start Date : January 2008
Primary Completion Date : March 2008
Study Completion Date : March 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin A
U.S. FDA Resources

Arms and Interventions

Intervention Details:
    Dietary Supplement: corn beta-carotene
    yellow corn beta-carotene in a 1 mg level to be taken as corn porridge in one meal by volunteers
    Other Name: staple food beta-carotene

Outcome Measures

Primary Outcome Measures :
  1. Bioavailability of corn beta-carotene and its equivalency to provide vitamin A [ Time Frame: one year ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   40 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy subjects

Exclusion Criteria:

  • GI track problems
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00636038


Locations
Zimbabwe
National University of Science and Technology
Bulawayo, Zimbabwe
Sponsors and Collaborators
Tufts University
Nutricia Research Fundation
National University of Science and Technology, Zimbabwe
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Guangwen Tang, Tufts University
ClinicalTrials.gov Identifier: NCT00636038     History of Changes
Other Study ID Numbers: 2007-E6
First Posted: March 14, 2008    Key Record Dates
Last Update Posted: March 14, 2008
Last Verified: March 2008

Keywords provided by Tufts University:
beta-carotene
yellow maize
vitamin A

Additional relevant MeSH terms:
Carotenoids
Beta Carotene
Antioxidants
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs
Provitamins
Vitamins
Micronutrients
Growth Substances