Effects of Vitamin A and Carotenoids on Iron Absorption

Not Applicable

Completed

• Conditions: Iron Absorption
• Interventions: Other: Labeled iron solutions

• Registration Number: NCT01493297
• Lead Sponsor: Swiss Federal Institute of Technology

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2011-09
• Primary Completion: 2011-11
• Study First Submitted: 2011-11-29
• Study First Submitted QC: 2011-12-13
• Study First Posted: 2011-12-15
• Study Completion: 2012-07
• Status Verified: 2014-01
• Last Update Submitted: 2014-01-22
• Last Update Posted: 2014-01-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 25

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Retinyl palmitate	Labeled iron solutions	Labeled iron as FeSO4 (4 mg) added to a test meal with or without retinyl palmitate (1000 RE)
Beta-carotene	Labeled iron solutions	Labeled iron as FeSO4 (4 mg) added to a test meal with or without beta-carotene (1000 RE)

Primary Outcome Measures

Name	Time	Method
Fractional iron absorption	1 month after enrollment	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.

Trial Locations

Locations (1)

Venezuelan Institute for Scientific Research (IVIC); 🇻🇪 Caracas, Venezuela