Clinical trial NCT01493297: Effects of Vitamin A and Carotenoids on Iron Absorption
Official title: Effects of Vitamin A and Carotenoids on Iron Absorption
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Iron Absorption
Keywords: Retinyl palmitate, beta-carotene, stable isotopes, radio isotopes
Lead sponsor: Swiss Federal Institute of Technology
Sponsor class: OTHER
Collaborators: name: Instituto Venezolano de Investigaciones Cientificas
First posted: 2011-12-15
Enrollment: 25
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 52
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.


Eligibility 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

Primary outcomes:
measure: Fractional iron absorption
timeFrame: 1 month after enrollment
Secondary outcomes:
Other outcomes:
Locations:
city: Caracas
country: Venezuela
facility: Venezuelan Institute for Scientific Research (IVIC)
Study officials:
affiliation: Swiss Federal Institute of Technology, ETH Zurich
name: Maria Andersson, Dr
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.
citation: Garcia-Casal MN. Carotenoids increase iron absorption from cereal based food in the human. Nutr Res 2006;26:340-4.
citation: 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.