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Updated: Aug 29, 2026

The Caco-2 Cell Bioassay for Measurement of Food Iron Bioavailability
Published on: April 28, 2022
Combined impact of pH and organic acids on iron uptake by Caco-2 cells
Susan Salovaara1, Ann-Sofie Sandberg, Thomas Andlid
1Department of Chemistry and Bioscience, Chalmers University of Technology, PO Box 5401, SE-402 29 Göteborg, Sweden.
Abstract:
Previous studies have shown that organic acids have an impact on both Fe(II) and Fe(III) uptake in Caco-2 cell. However, to what extent this effect is correlated with the anion of organic acids per se, or with the resulting decrease in pH, has not yet been clarified. Therefore, we studied the effect of five organic acids (tartaric, succinic, citric, oxalic, and propionic acid) on the absorption of Fe(II) and Fe(III) in Caco-2 cells and compared this with sample solutions without organic acids but set to equivalent pH by HCl. The results showed that the mechanisms behind the enhancing effect of organic acids differed for the two forms of iron. For ferric iron the organic acids promoted uptake both by chelation and by lowering the pH, whereas for ferrous iron the promoting effect was caused only by the lowered pH.
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