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Updated: Mar 29, 2026

The Caco-2 Cell Bioassay for Measurement of Food Iron Bioavailability
Published on: April 28, 2022
The effect of proteins from animal source foods on heme iron bioavailability in humans
Fernando Pizarro1, Manuel Olivares1, Carolina Valenzuela2
1Micronutrients Laboratory, Institute of Nutrition and Food Technology (INTA), University of Chile, Avda. El Líbano 5524, Santiago, Chile.
Abstract:
Forty-five women (35-45 year) were randomly assigned to three iron (Fe) absorption sub-studies, which measured the effects of dietary animal proteins on the absorption of heme Fe. Study 1 was focused on heme, red blood cell concentrate (RBCC), hemoglobin (Hb), RBCC+beef meat; study 2 on heme, heme+fish, chicken, and beef; and study 3 on heme and heme+purified animal protein (casein, collagen, albumin). Study 1: the bioavailability of heme Fe from Hb was similar to heme only (∼13.0%). RBCC (25.0%) and RBCC+beef (21.3%) were found to be increased 2- and 1.6-fold, respectively, when compared with heme alone (p<0.05). Study 2: the bioavailability from heme alone (10.3%) was reduced (p<0.05) when it was blended with fish (7.1%) and chicken (4.9%), however it was unaffected by beef. Study 3: casein, collagen, and albumin did not affect the bioavailability of Fe. Proteins from animal source foods and their digestion products did not enhance heme Fe absorption.
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