A method for preparing a composition; comprising: a. contacting a marine oil with an adsorbent comprising clay to provide a mixture, wherein the clay is present in an amount of from 5 to 7 wt.%, based on the weight of the oil; b. heating the mixture to from 150°C to 200°C, and c. removing the adsorbent from the mixture, to provide the composition, wherein the composition comprises less than 2.0 milligrams of cholesterol or ester thereof per gram of the composition.