Jarrow Formulas Freeze Dried Lactoferrin (Apolactoferrin/ultra low iron) is an important immune supporting glycoprotein that is found in breast milk. Digestion of lactoferrin by gastric pepsin liberates the immune-supporting peptide lactoferricin B. One of the biological activities of lactoferrin comes from its powerful ability to facilitate iron absorption. Freeze drying better preserves the delicate structure of the lactoferrin.