“…However, data published to date are inconclusive and sometimes controversial, due to different composition of the CPPs used (Ferraretto, Gravaghi, Fiorilli, & Tettamanti, 2003;Mora-Gutierrez, Farrell, Attaie, Mc Whinney, & Wang, 2007), to the experimental models used (animal or human) and the use of different CPPs sources (milk, calcium fortified milk, CPP endogenously present in milk, CPPs added to milk) or of different calcium sources (CaCO 3 , Ca-lactate) (Bennet et al, 2000;Heaney, Saito, & Orimo, 1994;Kopra, Scholz-Ahrens, & Barth, 1992;Lopez-Huertas et al, 2006;Narva, Kärkkäinen, Poussa, Lamberg-Allardt, & Korpela, 2003;Teucher et al, 2006;Tsuchita, Suzuki, & Kuwata, 2001). A better understanding of the relationships between intestinal calcium uptake and calciumeCPP interactions was provided by the observations that in cell models of the human intestine (HT-29 and Caco2 cells differentiated toward an intestinal phenotype) CPPs, a commercial preparation as well as single purified CPP, were able to promote calcium uptake (Cosentino et al, 2010;Ferraretto et al, 2003;Ferraretto, Signorile, Gravaghi, Fiorilli, & Tettamanti, 2001). A second relevant observation was that CPP-calcium aggregates, analogous to the ones formed by casein in milk (Holt, 1992;Rollema, 1992), constitute the form of CPPs needed for the calcium uptake effects (Gravaghi et al, 2007).…”