CholecalciferolErgocalciferols25-Hydroxyvitamin D 2Vitamin D DeficiencyCalcifediolVitamin DHydroxycholecalciferolsVitaminsAgaricusDietary SupplementsDihydroxycholecalciferolsParathyroid HormoneNebraskaDihydrotachysterolRickets24,25-Dihydroxyvitamin D 3PhosphorusCalcitriolSteroid HydroxylasesHydroxylationCholestanetriol 26-MonooxygenaseTrichosurusChickensCalcium, Dietary25-Hydroxyvitamin D3 1-alpha-HydroxylaseTreatment OutcomeIntestinal AbsorptionPest ControlReceptors, CalcitriolCalciumBone Density Conservation AgentsFood, FortifiedBone and BonesDuodenumTromethamineAdministration, OralDietSunlightCalcium RadioisotopesDouble-Blind MethodSeasons