Animal or vegetable oils are subjected to high vacuum distillation to obtain a fraction free of proteins and rancid products, and having an iodine value greater than 100, the fraction then being blended with vitamin concentrates.  Drying oils and semi-dryers such as perilla, linseed, n'gart, walnut, poppy seed, soya bean, sunflower, candle nut, corn, cottonseed and fish oils, rich in unsaturates, such as salmon, sardine, menhaden and cod liver are specified.  Short path high vacuum distillation is preferred.  Prior to distillation, hydrogen may be bubbled through the oil, which latter is then de-gassed in an apparatus heated to 100 DEG  C. and evacuated to a pressure of 100 mm. of mercury.  In an example linseed oil is subjected to short path high vacuum distillation.  The fraction collected at 190 DEG  C. and under a pressure of 5 x 10-2 millimetres of mercury comprises a mixture of free fatty acids and sterols. Fractions p  collected between 225-250 DEG  C. and at pressures between 0,5 to 3 x 10-2 millimetres of mercury comprise the desired fractions for blending with vitamin concentrates, and contain glycerides corresponding to over 88 per cent of unsaturated fatty acid.  For medicinal uses, lecithin may be added to the mixture; the oil may be emulsified, or flavouring materials may be admixed.  The vitamin concentrates may be obtained from the source of oil, such as fish oils.  British Specification 485,614, and U.S.A. Specifications 1,925,559 and 1,942,858 are referred to.ALSO:In the short-path high vacuum distillation of crude linseed oil the first distillate taken off at a temperature of 190 DEG  C. and pressure of 5 x 10-2 millimetres of mercury comprises a mixture of free fatty acids and sterols.  British Specification 485,614, [Group III], and U.S.A. Specifications 1,925,559 and 1,942,858 are referred to.ALSO:In the preparation of a medicinal composition, animal or vegetable oils are subjected to high vacuum distillation to obtain a fraction free of proteins and rancid products and having an iodine value greater than 100, the fraction then being blended with vitamin concentrates. Drying oils and semi-dryers such as perilla, linseed, N'Gart, walnut, poppy seed, soya bean, sunflower, candle nut, corn, cottonseed and fish oils, rich in unsaturates, such as salmon, sardine, menhaden and cod liver are specified.  Short path high vacuum distillation is preferred. Applied to linseed oil, fractions collected between 225-250 DEG  C. and at pressures between 0,5 to 3 x 10-2 mms. of mercury comprise the desired fractions and contain glycerides corresponding to over 88 per cent of unsaturated fatty acid. Lecithin may be added to the mixture.  The vitamin concentrates may be obtained from the source of oil, such as fish oils. British Specification 485,614. [Group III], and U.S.A. Specifications 1,925,559, and 1,942,858 are referred to.ALSO:In the preparation of a food fat, animal or vegetable oils are subjected to high vacuum distillation to obtain a fraction free of proteins and rancid products and having an iodine value greater than 100, the fraction then being blended with vitamin concentrates.  Drying oils and semi-dryers such as perilla, linseed, N'Gart, walnut, poppy seed, soya bean, sunflower, candle nut, corn, cottonseed and fish oils, rich in unsaturates such as salmon, sardine, menhaden and cod liver are specified.  Shortpath high vacuum distillation is preferred. Applied to linseed oil, fractions collected between 225-250 DEG  C. and at pressures between 0,5 to 3 x 10-2 mms. of mercury comprise the desired fractions and contain glycerides corresponding to over 88 per cent of unsaturated fatty acid.  The oil may be emulsified and flavouring materials may be admixed.  The vitamin concentrates may be obtained from the source of oil, such as fish oils.  British Specification 485,614, [Group III], and U.S.A. Specifications 1,925,559 and 1,942,858 are referred to.