Inhibitory effect of calcium on non-heme iron absorption may be related to translocation of DMT-1 at the apical membrane of enterocytes

Ben A V Thompson, Paul A Sharp, Ruan Elliott, Susan J Fairweather-Tait

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43 Citations (Scopus)


Many studies show that calcium reduces iron absorption from single meals, but the underlying mechanism is not known. We tested the hypothesis that calcium alters the expression and/or functionality of iron transport proteins. Differentiated Caco-2 cells were treated with ferric ammonium citrate and calcium chloride, and ferritin, DMT-1, and ferroportin were quantified in whole-cell lysate and cell-membrane fractions. Calcium attenuated the iron-induced increase in cell ferritin levels in a dose-dependent manner; a significant decrease was seen at calcium concentrations of 1.25 and 2.5 mM but was only evident after a 16-24 h incubation period. Calcium and iron treatments decreased DMT-1 protein in Caco-2 cell membranes, although total DMT-1 in whole cell lysates was unchanged by either iron or calcium. No change was seen in ferroportin expression. Our data suggest that calcium reduces iron bioavailability by decreasing DMT-1 expression at the apical cell membrane, thereby downregulating iron transport into the cell.
Original languageEnglish
Pages (from-to)8414-8417
Number of pages4
JournalJournal of Agricultural and Food Chemistry
Issue number14
Publication statusPublished - 28 Jul 2010


  • Biological Transport
  • Caco-2 Cells
  • Calcium
  • Cation Transport Proteins
  • Cell Membrane
  • Down-Regulation
  • Enterocytes
  • Humans
  • Intestinal Absorption
  • Iron
  • Protein Transport

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