Effects of Vitamin A and Carotenoids on Iron Absorption

This study has been completed.
Sponsor:
Collaborator:
Instituto Venezolano de Investigaciones Cientificas
Information provided by (Responsible Party):
Prof. Michael B. Zimmermann, Swiss Federal Institute of Technology
ClinicalTrials.gov Identifier:
NCT01493297
First received: November 29, 2011
Last updated: January 22, 2014
Last verified: January 2014
  Purpose

The objective of this study is to investigate the effect of vitamin A and carotenoids on iron absorption in healthy subjects with low and normal vitamin A status. Vitamin A and carotenoids have been reported to enhance the nonheme iron absorption, but the results from human isotope studies are equivocal. Radio-iron studies in Venezuelan adults have consistently reported an increase in iron absorption, whereas stable and radio isotopes studies conducted in Sweden and Switzerland reported no influence. Differences in vitamin A status of the subjects may be a possible explanation for the contradictory findings. In this study, iron absorption will be measured from an iron-fortified maize bread meal with or without retinyl palmitate or β-carotene by using both stable- and radioactive-isotope techniques in Venezuelan women with a range of vitamin A status.


Condition Intervention
Iron Absorption
Other: Labeled iron solutions

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Bio-availability Study
Intervention Model: Crossover Assignment
Masking: Single Blind (Subject)
Primary Purpose: Basic Science
Official Title: Effects of Vitamin A and Carotenoids on Iron Absorption

Resource links provided by NLM:


Further study details as provided by Swiss Federal Institute of Technology:

Primary Outcome Measures:
  • Fractional iron absorption [ Time Frame: 1 month after enrollment ] [ Designated as safety issue: No ]
    Iron absorption will be estimated by measuring the erythrocyte incorporation of stable (57Fe/58Fe) and radio (55Fe/59Fe) iron isotopes labels given in test meals.


Enrollment: 25
Study Start Date: September 2011
Study Completion Date: July 2012
Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Retinyl palmitate
Labeled iron as FeSO4 (4 mg) added to a test meal with or without retinyl palmitate (1000 RE)
Other: Labeled iron solutions
Labeled iron as FeSO4 (4 mg/test meal)
Beta-carotene
Labeled iron as FeSO4 (4 mg) added to a test meal with or without beta-carotene (1000 RE)
Other: Labeled iron solutions
Labeled iron as FeSO4 (4 mg/test meal)

  Eligibility

Ages Eligible for Study:   18 Years to 52 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Women 18-52 years old
  • Body weight ≤ 70 kg
  • Body mass index (BMI), 18.5-30 kg/m2
  • Adequate vitamin A status (SR ≥ 0.7 μmol/L, n=20)
  • Inadequate vitamin A status (SR < 0.7 μmol/L, n=20)
  • No major medical illnesses (no known infection, gastrointestinal or metabolic disorders)

Exclusion Criteria:

  • Pregnancy or lactation
  • Regular intake of medication (except oral contraceptives)
  • Blood donation or significant blood loss (accident, surgery) over the past 4 months
  • Currently participating in another clinical trial or having participated in another clinical trial during the last 3 months prior to the beginning of this study
  • Former participation in a study involving administration of iron stable isotopes
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01493297

Locations
Venezuela
Venezuelan Institute for Scientific Research (IVIC)
Caracas, Venezuela, 1020-A
Sponsors and Collaborators
Swiss Federal Institute of Technology
Instituto Venezolano de Investigaciones Cientificas
Investigators
Principal Investigator: Maria Andersson, Dr Swiss Federal Institute of Technology, ETH Zurich
  More Information

Publications:
Responsible Party: Prof. Michael B. Zimmermann, Principal investigator, Swiss Federal Institute of Technology
ClinicalTrials.gov Identifier: NCT01493297     History of Changes
Other Study ID Numbers: ETH-FeVZ
Study First Received: November 29, 2011
Last Updated: January 22, 2014
Health Authority: Switzerland: Ethikkommission

Keywords provided by Swiss Federal Institute of Technology:
Retinyl palmitate, beta-carotene, stable isotopes, radio isotopes

Additional relevant MeSH terms:
Carotenoids
Retinol palmitate
Vitamin A
Vitamins
Beta Carotene
Iron
Antioxidants
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Protective Agents
Physiological Effects of Drugs
Micronutrients
Growth Substances
Anticarcinogenic Agents
Antineoplastic Agents
Therapeutic Uses
Trace Elements

ClinicalTrials.gov processed this record on July 28, 2014