Effects of Vitamin A and Carotenoids on Iron Absorption

Iron Absorption Clinical Trial

Official title:

Effects of Vitamin A and Carotenoids on Iron Absorption

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01493297
• Other study ID #: ETH-FeVZ
• Status: Completed
• Phase: N/A
• First received: November 29, 2011
• Last updated: January 22, 2014
• Start date: September 2011
• Est. completion date: July 2012

Study information

• Verified date: January 2014
• Source: Swiss Federal Institute of Technology
• Contact: n/a
• Is FDA regulated: No
• Health authority: Switzerland: Ethikkommission
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: July 2012
• Est. primary completion date: November 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 52 Years

Eligibility

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

Allocation: Non-Randomized, Endpoint Classification: Bio-availability Study, Intervention Model: Crossover Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Iron Absorption

Intervention

Other:
• Labeled iron solutions
Labeled iron as FeSO4 (4 mg/test meal)

Locations

Country	Name	City	State
Venezuela	Venezuelan Institute for Scientific Research (IVIC)	Caracas

Sponsors (2)

Lead Sponsor	Collaborator
Swiss Federal Institute of Technology	Instituto Venezolano de Investigaciones Cientificas

Country where clinical trial is conducted

Venezuela, 

References & Publications (4)

García-Casal MN, Layrisse M, Solano L, Barón MA, Arguello F, Llovera D, Ramírez 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. — View Citation

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

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.

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	No