Vitamin D25-Hydroxyvitamin D 2Vitamin D DeficiencyCalcifediolCholecalciferol25-Hydroxyvitamin D3 1-alpha-HydroxylaseSunlightErgocalciferolsParathyroid HormoneSeasonsDietary SupplementsHydroxycholecalciferolsOsteomalaciaDihydroxycholecalciferolsVitaminsFood, Fortified24,25-Dihydroxyvitamin D 3Steroid HydroxylasesVitamin D-Binding ProteinRicketsBone DensityNutritional StatusCalcitriolCross-Sectional StudiesCholestanetriol 26-MonooxygenaseCalciumLinear ModelsEuropean Continental Ancestry GroupAbsorptiometry, PhotonMilkPostmenopauseReceptors, CalcitriolRisk FactorsAfrican AmericansCalcium, DietarySkin PigmentationPhosphorusBone Density Conservation AgentsBone and BonesNutritional RequirementsProspective StudiesDietHydroxylationPrevalenceMongoliaBiological MarkersCase-Control StudiesCohort StudiesBreadNutrition SurveysPhosphatesHypercalcemiaKidneyAlkaline PhosphataseRadioimmunoassayNutrition PolicyCytochrome P-450 Enzyme SystemBody Mass IndexHyperparathyroidism, SecondaryDouble-Blind MethodMaternal Nutritional Physiological PhenomenaTandem Mass SpectrometryUnited StatesChromatography, High Pressure LiquidHyperparathyroidismChromatography, LiquidIntestinal AbsorptionLogistic ModelsHip FracturesMultivariate AnalysisCholestenesFinlandHypoparathyroidismDehydrocholesterolsOdds RatioReference Values2,4-Dichlorophenoxyacetic AcidPregnancyRenal Insufficiency, ChronicAfrican Continental Ancestry GroupOsteoporosis, PostmenopausalMaineFollow-Up StudiesBone ResorptionPremenopauseUltraviolet RaysBostonRegression AnalysisFrail ElderlyAge FactorsDose-Response Relationship, DrugMass SpectrometryOsteoporosisFractures, BoneNutrition AssessmentAdrenodoxinObesityNebraskaLongitudinal StudiesTime Factors