In studies on man relating to vitamin A, reduced ability to absorb the vitamin was found in 1 patient with old intestinal tuberculosis. This suggested that investigation of patients with intestinal symptoms associated with tuberculosis should be made by means of the vitamin A absorption test. This vitamin A absorption test is somewhat similar to the dextrose tolerance test. The patient is given a known amount of vitamin A in the form of a concentrated fish liver oil by mouth (7,000 U. S. P. units per kilogram of body weight). Blood samples are taken before the oil is given and at four, eight and twenty-four hours after the ingestion of the oil. These blood samples are then analyzed chemically for the vitamin A concentration.1 Normally there is a decided rise in the blood concentration of vitamin A which usually reaches a peak at the fourth hour. Since vitamin A