Folates are absorbed primarily in the duodenum and jejunum within the acid microenvironment at the cell surface, because the human proton-coupled folate transporter (hPCFT) has recently been identified as a pH-dependent folic acid transporter. High levels of PCFT are expressed in apical brush-border membranes in the proximal jejunum and duodenum; Pteroylpolyglutamates, the predominate form of dietary folates, are hydrolyzed to the monoglutamate form during intestinal absorption by the enzyme pteroylpolyglutamate hydrolase (PPH). Two PPH exist in the intestinal mucosa: a soluble intracellular PPH that is active at acidic pH, and an insoluble PPH on the brush border surface that is active at more neutral pH. It was reported that free folates are absorbed mainly in jejunum, whereas FBP-bound (Folate binding proteins in dairy) folates are absorbed more efficiently in ileum. Basically, this proximal absorption fact of the duodenum is fairly new.