title: Cholecalciferol and 25-hydroxycholecalciferol content of chicken egg yolk as affected by the cholecalciferol content of feed.
abstract: The predominant source of vitamin D is the synthesis of cholecalciferol in the skin by the action of sunlight; however, due to the relative lack of sunlight, the intake of vitamin D from food is emphasized during winter, especially in the northern countries. Only a few foods (fish, eggs, wild mushrooms, meat, and milk) are natural sources of vitamin D. In addition, the content of vitamin D in foods is generally low, and some groups of people obtain amounts of vitamin D that are too small from their diet. The present study was designed to determine whether it is possible to increase the vitamin D content of egg yolk by giving hens feed containing elevated levels of cholecalciferol. Three cholecalciferol levels were tested: 26.6 (1064), 62.4 (2496), and 216 microgram (8640 IU)/kg feed. Egg yolk samples were taken after 0, 4, 5, and 6 weeks and were assayed for the presence of cholecalciferol and 25-hydroxycholecalciferol using an HPLC method. According to the present study, there was strong positive correlation between cholecalciferol content in poultry feed and cholecalciferol (r = 0. 995) and 25-hydroxycholecalciferol (r = 0.941) content in egg yolk.
authors.affiliation: Agricultural Research Centre of Finland, FIN-316 000, Jokioinen, Finland. Pirjo.Mattila@mtt.fi
authors.forename: P
authors.initials: P
authors.lastname: Mattila
authors.forename: K
authors.initials: K
authors.lastname: Lehikoinen
authors.forename: T
authors.initials: T
authors.lastname: Kiiskinen
authors.forename: V
authors.initials: V
authors.lastname: Piironen
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002112:Calcifediol / Q000032:analysis*; D002645:Chickens; D002762:Cholecalciferol / Q000032:analysis*; D004530:Egg Yolk / Q000737:chemistry*; D005260:Female; D005527:Food, Fortified
chemical_list: D002762:Cholecalciferol; D002112:Calcifediol