Effects of Vitamin A and Carotenoids on Iron Absorption

Federal Institute of Technology (ETH) Zurich

Status

Completed

Conditions

Iron Absorption

Treatments

Other: Labeled iron solutions

Study type

Interventional

Funder types

Other

Identifiers

NCT01493297

ETH-FeVZ

Details and patient eligibility

About

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.

Enrollment

25 patients

Sex

Female

Ages

18 to 52 years old

Volunteers

Accepts Healthy Volunteers

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