Vit. A in halibut intestinal oil exists almost entirely (c. 95%) as esters. Halibut intestines readily autolyse and the extractable oil is a mixture of free fatty acids, free cholesterol and free vit. A with these esters. The oil is also contaminated with phosphatides and other products, including a water-sol. material with u. v. absorption max. at 261 mu. Molecular distillation of oil partially freed from free acids was carried out and elimination curves constructed. The curves for vitamins A and A2 are very similar.