The "folic acid" content of cow's milk, as listed in the report of the Committee on Nutrition (Pediatrics, 31:329, 1963) is probably too low, as pointed out by Drs. Naiman and Oski. We would agree that these figures should be withdrawn until a more accurate assessment can be made. We are, however, less certain than they appear to be, that the L. casei assay, ascorbate-protected, will provide the information desired, i.e., the true total folate content of foodstuff biologically available to the human. For an understanding of the present situation, it is necessary to review briefly certain pertinent developments in this field.