NCT01493297

Brief Summary

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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
25

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Sep 2011

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

September 1, 2011

Completed
2 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 1, 2011

Completed
28 days until next milestone

First Submitted

Initial submission to the registry

November 29, 2011

Completed
16 days until next milestone

First Posted

Study publicly available on registry

December 15, 2011

Completed
7 months until next milestone

Study Completion

Last participant's last visit for all outcomes

July 1, 2012

Completed
Last Updated

January 23, 2014

Status Verified

January 1, 2014

Enrollment Period

2 months

First QC Date

November 29, 2011

Last Update Submit

January 22, 2014

Conditions

Iron Absorption

Keywords

Retinyl palmitate, beta-carotene, stable isotopes, radio isotopes

Outcome Measures

Primary Outcomes (1)

  • Fractional iron absorption

    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.

    1 month after enrollment

Study Arms (2)

Retinyl palmitate

OTHER

Labeled iron as FeSO4 (4 mg) added to a test meal with or without retinyl palmitate (1000 RE)

Other: Labeled iron solutions

Beta-carotene

OTHER

Labeled iron as FeSO4 (4 mg) added to a test meal with or without beta-carotene (1000 RE)

Other: Labeled iron solutions

Interventions

Labeled iron solutionsOTHER

Labeled iron as FeSO4 (4 mg/test meal)

Beta-caroteneRetinyl palmitate

Eligibility Criteria

Age18 Years - 52 Years
Sexfemale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • 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)

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Venezuelan Institute for Scientific Research (IVIC)

Caracas, 1020-A, Venezuela

Location

Related Publications (4)

  • Walczyk T, Davidsson L, Rossander-Hulthen L, Hallberg L, Hurrell RF. No enhancing effect of vitamin A on iron absorption in humans. Am J Clin Nutr. 2003 Jan;77(1):144-9. doi: 10.1093/ajcn/77.1.144.

    PMID: 12499334BACKGROUND

  • Garcia-Casal MN, Layrisse M, Solano L, Baron MA, Arguello F, Llovera D, Ramirez J, Leets I, Tropper E. Vitamin A and beta-carotene can improve nonheme iron absorption from rice, wheat and corn by humans. J Nutr. 1998 Mar;128(3):646-50. doi: 10.1093/jn/128.3.646.

    PMID: 9482776BACKGROUND

  • Garcia-Casal MN. Carotenoids increase iron absorption from cereal based food in the human. Nutr Res 2006;26:340-4.

    BACKGROUND

  • Layrisse M, Garcia-Casal MN, Solano L, et al. The role of vitamin A on the inhibitors of nonheme iron absorption: preliminary results. J Nutr Biochem 1997;8:61-7.

    BACKGROUND

Study Officials

  • Maria Andersson, Dr

    Swiss Federal Institute of Technology, ETH Zurich

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Principal investigator

Study Record Dates

First Submitted

November 29, 2011

First Posted

December 15, 2011

Study Start

September 1, 2011

Primary Completion

November 1, 2011

Study Completion

July 1, 2012

Last Updated

January 23, 2014

Record last verified: 2014-01

Locations

VE(1)