Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation
Hilty FM., Arnold M., Hilbe M., Teleki A., Knijnenburg JTN., Ehrensperger F., Hurrell RF., Pratsinis SE., Langhans W., Zimmermann MB.
Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO 4), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area ∼190m2 g-1) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO4 and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO 4 and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value. © 2010 Macmillan Publishers Limited. All rights reserved.