Absorption and Utilization of Polyglutamyl Forms of Folate in Man

Some three-quarters of folate compounds in a normal mixed diet have a chain of seven glutamic acid residues (polyglutamates). The extent to which these forms of folate are absorbed and utilized by man is of considerable nutritional importance. These studies indicate that the polyglutamate forms were absorbed and utilized to about one-third of the extent of simpler (monoglutamate) forms, as judged by the serum folate levels after oral equimolar doses, by the amount incorporated into red cells in long-term studies, by the amount excreted into the urine, and by their capacity to initiate haematological responses in patients with folate-deficient megaloblastic anaemias.