Bioavailability of Yellow Maize Carotenoids in Humans

This study has been completed.
Sponsor:
Collaborators:
Nutricia Research Fundation
National University of Science and Technology, Bulawayo, Zimbabwe
Information provided by:
Tufts University
ClinicalTrials.gov Identifier:
NCT00636038
First received: March 7, 2008
Last updated: March 13, 2008
Last verified: March 2008
  Purpose

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 Intervention Phase
Vitamin A Status
Dietary Supplement: corn beta-carotene
Phase 1

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Bio-equivalence Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science

Resource links provided by NLM:


Further study details as provided by Tufts University:

Primary Outcome Measures:
  • Bioavailability of corn beta-carotene and its equivalency to provide vitamin A [ Time Frame: one year ] [ Designated as safety issue: No ]

Enrollment: 8
Study Start Date: January 2008
Study Completion Date: March 2008
Primary Completion Date: March 2008 (Final data collection date for primary outcome measure)
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
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.

  Eligibility

Ages Eligible for Study:   40 Years to 70 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy subjects

Exclusion Criteria:

  • GI track problems
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: 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, Bulawayo, Zimbabwe
  More Information

No publications provided by Tufts University

Additional 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
Study First Received: March 7, 2008
Last Updated: March 13, 2008
Health Authority: Zimbabwe: Medical Research Council

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

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

ClinicalTrials.gov processed this record on April 16, 2014