Effects of Iron Source on Iron Availability from Casein and Casein Phosphopeptides

: Iron availability from FeSO4 in samples containing sodium caseinate (SC), casein phosphopeptides (CPP) or whey protein concentrate (WPC), and from ferric citrate (Fe‐CA) in samples containing SC or CPP was measured using an in vitro digestion/Caco‐2 cell culture model. In FeSO4 spiked samples, relative availability was CPP > SC, CPP = WPC, and CPP = FeSO4 alone. In samples containing Fe‐CA, a soluble iron chelate, relative availability was CPP = SC and CPP < Fe‐CA alone. These results suggest that CPP enhances iron availability from foods with low availability but does not improve and may inhibit availability from soluble iron species.