Casein micelles contain stabilized amorphous calcium phosphate that is bioavailable to the neonate (Holt & Sawyer, 1988). Tryptic phosphopeptides formed from casein digestion associate with amorphous calcium phosphate forming stable nanocomplexes that have been described as calcium phosphate delivery vehicles (Holt et al. 1996; Reynolds et al. 1999, 2003; Farrell et al. 2002).