Lactoferrin (lactotransferrin; Lf) is an iron-binding glycoprotein and one of 
the most important bioactivators in milk and other external secretions. It has 
numerous biological roles, including the regulation of iron absorption and 
modulation of immune responses, and has anti-microbial, anti-viral, antioxidant, 
anti-cancer, and anti-inflammatory activities. Lf regulates the quantity of iron 
absorbed in the intestine via its role in iron transport and can also chelate 
iron, directly or indirectly. Notably, it has been used as an adjuvant therapy 
for some intestinal diseases. It is now used in nutraceuticalsupplemented infant 
formula and other food products. This article reviews the content, distribution, 
physiologic functions and current applications of Lf, and aims to shed light on 
future prospects for additional applications of Lf.