Löhr's1investigations of the wound-healing properties of cod liver oil have stimulated many clinical studies. Of special interest is the work of Banyai,2who successfully treated lupus with topical applications of cod liver oil. In our laboratory the healing effect of cod liver oil applied topically to experimental tuberculous ulcers of the skin of guinea pigs has been demonstrated, and similar favorable results with certain fractions, obtained in the attempt to isolate the active substance, have been reported by Getz.3Since the fractions most active in the healing of tuberculous lesions are those containing the greatest amounts of vitamin A, the queries arise Are tuberculous individuals deficient in vitamin A? Will tuberculous human beings respond favorably to increased amounts of vitamin A? Are "normal" persons deficient in vitamin A? To answer these questions, the study here reported was conceived. The work of Jeans, Blanchard and Zentmire4