POSSIBLE FACTORS RESPONSIBLE FOR THE HIGH VARIATION IN THE CHOLECALCIFEROL CONTENTS OF FISH

Previously a high variation was found in the cholecalciferol (vitamin D-3) contents of fish samples representing the same species but caught in different habitats in Finland. The present study was designed to p rovide reasons for this variation. The influences of various; factors, e.g. weight, age, and sex of the fish as well as the cholecalciferol content of zooplankton, on the cholecalciferol contents. of fish flesh were studied. Perch, vendace, and pike samples were caught in three d ifferent types of lakes, and perch, Baltic herring, and pike samples w ere caught in the Baltic Sea. Zooplankton samples were caught in all f our habitats. The cholecalciferol determinations were performed with H PLC after purification with preparative HPLC. No consistent relationsh ip between the weight, sex, or age of the fish and cholecalciferol con tent was found. According to this study, it is possible that diet is a likely factor which causes the variation in the cholecalciferol conte nts of the fish.