Activity of Citrovorum Factor it or the Chick.

Abstract
Crystalline citrovorum factor (CF) obtained from horse liver was approx. as active as pteroylglutamic acid in counteracting folic acid deficiency in the chick. CF was somewhat more active than leucovorin. CF, leucovorin, and folinic acid-SF when fed in the diet were substantially less active than pteroylglutamic acid.