In the report of the Committee on Nutrition concerning the nutritional adequacy of cow's milk substitutes (Pediatrics, 31:329, 1963) we noted that the folic acid content of cow's milk was stated to be 2.2 µg per quart.
This figure was obtained by microbiologic assay with Streptococcus fecalis1; no added ascorbic acid was used in the incubation medium to protect labile folates from oxidative destruction.