25-Hydroxyvitamin D3 1-alpha-HydroxylaseVitamin DSunlightMilk SubstitutesCholesterol 7-alpha-HydroxylaseVitamin D DeficiencyCalcifediol25-Hydroxyvitamin D 2CholecalciferolHydroxycholecalciferolsErgocalciferolsVitaminsSteroid HydroxylasesDihydroxycholecalciferols24,25-Dihydroxyvitamin D 3CalcitriolReceptors, CalcitriolVitamin AParathyroid HormoneVitamin D-Binding ProteinCholestanetriol 26-MonooxygenaseRicketsVitamin EDietary SupplementsPhenylalanine HydroxylaseSteroid 21-HydroxylaseVitamin B 12SeasonsVitamin A DeficiencyCalcium, DietaryHydroxylationTryptophan HydroxylaseCalciumOsteomalaciaPhosphorusTyrosine 3-MonooxygenaseCytochrome P-450 Enzyme SystemBone DensityMixed Function OxygenasesNutritional StatusVitamin K 1Bone and BonesProcollagen-Proline DioxygenaseDietCross-Sectional StudiesBone Density Conservation AgentsSkin PigmentationKineticsChromatography, High Pressure LiquidKidneyRisk FactorsVitamin B 6Vitamin E DeficiencyVitamin B 12 DeficiencyBiological MarkersRNA, MessengerFood, FortifiedMolecular Sequence DataProspective StudiesBase SequenceNutritional RequirementsLinear ModelsCase-Control StudiesTime FactorsPhosphatesDose-Response Relationship, DrugAscorbic AcidVitamin K DeficiencyDehydrocholesterolsPrevalenceNutrition PolicyHypercalcemiaLiverCells, CulturedOsteoporosisVitamin B 6 DeficiencyEuropean Continental Ancestry GroupHypoparathyroidismHyperparathyroidism, SecondaryVitamin D Response ElementIntestinal AbsorptionCohort StudiesHypocalcemiaAlkaline PhosphataseDouble-Blind MethodMass SpectrometryPregnancyalpha 1-AntitrypsinNutrition SurveysBenzopyrene HydroxylaseAdrenal Hyperplasia, CongenitalFractures, BoneOsteocalcinRadioimmunoassayHypoxia-Inducible Factor 1, alpha SubunitAmino Acid SequenceProtein BiosynthesisCell Line4-Hydroxybenzoate-3-MonooxygenaseCloning, Molecular