Vitamin A activity in foods of animal origin

Abstract
The vitamin A activity of 246 samples of 59 different foods of animal origin was determined by high performance liquid chromatography. Wherever possible, the amounts of all‐trans retinol, 13‐cis‐ retinol, dehydroretinol, retinaldehyde and β‐carotene were measured. The relative activity of these components is discussed, and the results compared with previous estimates of the vitamin A content of these foods.