Lingcod liver oil unsaponifiable material was separated into three main fractions by means of an aluminum oxide column. Major components of the three fractions were vitamin A, cholesterol, and glyceryl ethers, respectively. These fractions were given as dietary supplements to cholesterol-fed chicks and the effect of the supplements on the hypercholesterolemia induced by the cholesterol feeding was investigated. The fraction containing vitamin A prevented the hypercholesterolemia. Crystalline vitamin A acetate produced a similar effect when it was added as a dietary supplement. It was concluded that vitamin A was probably the hypocholesterolemic agent in lingcod liver oil although other compounds in the oil may also exert some influence on the control of the serum cholesterol concentrations in the chicks.
The Origin of the Vitamin A in Fish Oils and Fish Liver Oils