title: Effect of short-term UVB exposure on vitamin D concentration of eggs and vitamin D status of laying hens.
abstract: Vitamin D deficiency in humans is widespread, and only a few food items are important natural sources of vitamin D. This study investigated the effect of UVB exposure of laying hens on the vitamin D content in egg yolk. In a two-factorial design, hens fed a vitamin D-deficient (-D) or -adequate (+D) diet were nonexposed or exposed to UVB light over a period of 4 weeks. UVB exposure of the -D group caused nearly normal egg production rate and egg shell quality; exposure of the +D group did not further improve these parameters. UVB exposure tended to improve the concentration of plasma 25-hydroxycholecalciferol (25(OH)D(3)), but had no effect on 1,25-dihydroxycholecalciferol in plasma or on cholecalciferol and 25(OH)D(3) in egg yolk. The present study shows that a short-term exposure of laying hens to UVB light is not an appropriate way to improve the vitamin D content of egg yolk.
authors.affiliation: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, D-06108 Halle, Germany.
authors.forename: Julika
authors.initials: J
authors.lastname: Lietzow
authors.forename: Holger
authors.initials: H
authors.lastname: Kluge
authors.forename: Corinna
authors.initials: C
authors.lastname: Brandsch
authors.forename: Nicole
authors.initials: N
authors.lastname: Seeburg
authors.forename: Frank
authors.initials: F
authors.lastname: Hirche
authors.forename: Markus
authors.initials: M
authors.lastname: Glomb
authors.forename: Gabriele I
authors.initials: GI
authors.lastname: Stangl
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004531:Eggs / Q000032:analysis* / Q000528:radiation effects*; D005260:Female; D052287:Oviparity / Q000528:radiation effects; D011201:Poultry Diseases / Q000378:metabolism / Q000503:physiopathology / Q000532:radiotherapy*; D014466:Ultraviolet Rays; D014467:Ultraviolet Therapy; D014807:Vitamin D / Q000032:analysis* / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000378:metabolism / Q000503:physiopathology / Q000532:radiotherapy / Q000662:veterinary*
chemical_list: D014807:Vitamin D