title: Seasonal variation of provitamin D2 and vitamin D2 in perennial ryegrass (Lolium perenne L.).
abstract: Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times during the season, and the contents of vitamin D(2) and ergosterol were analyzed by a sensitive and selective liquid chromatography tandem mass spectrometry method. Weather factors were recorded, and a principal component analysis was performed to study which factors were important for the formation of vitamin D(2). The results suggest that a combination of weather factors is involved and that the contents of ergosterol and vitamin D(2) change more than a factor of 10 during the season. These results demonstrate that grass potentially can be a significant source of vitamin D for grazing animals and animals fed on silage and hay.
authors.affiliation: Division of Food Chemistry, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark. riba@food.dtu.dk
authors.forename: Rie Bak
authors.initials: RB
authors.lastname: Jäpelt
authors.forename: Thomas
authors.initials: T
authors.lastname: Didion
authors.forename: Jørn
authors.initials: J
authors.lastname: Smedsgaard
authors.forename: Jette
authors.initials: J
authors.lastname: Jakobsen
mesh_terms: D004872:Ergocalciferols / Q000032:analysis*; D004875:Ergosterol / Q000032:analysis*; D008129:Lolium / Q000737:chemistry*; D012621:Seasons; D013696:Temperature; D014887:Weather
chemical_list: D004872:Ergocalciferols; D004875:Ergosterol