2023
Genetic variants in the vitamin D pathway and their association with vitamin D metabolite levels: Detailed studies of an inner-city pediatric population suggest a modest but significant effect in early childhood
Fu L, Wong B, Li Z, Horst R, Williams R, Lee B, Miller J, Carpenter T, Cole D. Genetic variants in the vitamin D pathway and their association with vitamin D metabolite levels: Detailed studies of an inner-city pediatric population suggest a modest but significant effect in early childhood. The Journal Of Steroid Biochemistry And Molecular Biology 2023, 233: 106369. PMID: 37490983, DOI: 10.1016/j.jsbmb.2023.106369.Peer-Reviewed Original ResearchConceptsVitamin D pathwayD binding proteinPediatric populationInner-city pediatric populationVitamin D metabolite levelsVitamin D insufficiencyRisk pediatric populationsVitamin D metabolismVitamin D binding proteinVitamin D metabolitesD pathwayMonths of ageSanger sequencing confirmationD insufficiencyHealthy infantsD metabolismD levelsD metabolitesMultivariate regression modelLarge cohortMetabolite levelsRelevant associationsPotential roleEarly childhoodInter-individual differences
2019
Relationship of Total and Free 25-Hydroxyvitamin D to Biomarkers and Metabolic Indices in Healthy Children
Simpson CA, Zhang JH, Vanderschueren D, Fu L, Pennestri TC, Bouillon R, Cole DEC, Carpenter TO. Relationship of Total and Free 25-Hydroxyvitamin D to Biomarkers and Metabolic Indices in Healthy Children. The Journal Of Clinical Endocrinology & Metabolism 2019, 105: dgz230. PMID: 31774125, PMCID: PMC7174047, DOI: 10.1210/clinem/dgz230.Peer-Reviewed Original ResearchConceptsBody mass indexVitamin D statusParathyroid hormoneUrban-dwelling childrenD statusGC haplotypeHomeostatic model assessmentSystolic blood pressureAcademic medical centerHeathy childrenBlood pressureClinical outcomesMass indexInsulin resistanceHealthy childrenMedical CenterMetabolic indicesModel assessmentRegistration noOutcome variablesHispanic backgroundChildrenStrongest correlateInsulinAvailable assessmentsHigh dose vitamin D supplementation does not rescue bone loss following Roux-en-Y gastric bypass in female rats
Niu A, Carpenter TO, Grams JM, Bozorgmehri S, Tommasini SM, Schafer AL, Canales BK. High dose vitamin D supplementation does not rescue bone loss following Roux-en-Y gastric bypass in female rats. Bone 2019, 127: 172-180. PMID: 31226531, PMCID: PMC6708762, DOI: 10.1016/j.bone.2019.06.015.Peer-Reviewed Original ResearchConceptsCalcium/creatinine ratioVitamin D supplementationSecondary hyperparathyroidismBone lossD supplementationGastric bypassGut hormonesRYGB groupParathyroid hormoneFracture riskFemale ratsUrine calcium/creatinine ratioBone volumeUrinary calcium/creatinine ratioHigh-dose vitamin D supplementationAdequate vitamin D supplementationC-terminal telopeptide (CTX) levelsHigher serum parathyroid hormoneIU vitamin D supplementationIU vitamin D/Bone phenotypeDose vitamin D supplementationResultant secondary hyperparathyroidismVitamin D/Serum parathyroid hormone
2017
CYP24A1 loss of function: Clinical phenotype of monoallelic and biallelic mutations
Carpenter TO. CYP24A1 loss of function: Clinical phenotype of monoallelic and biallelic mutations. The Journal Of Steroid Biochemistry And Molecular Biology 2017, 173: 337-340. PMID: 28093352, DOI: 10.1016/j.jsbmb.2017.01.006.Peer-Reviewed Original ResearchConceptsVitamin D metabolismD metabolismParathyroid hormoneActive vitamin D metaboliteVitamin D supplementationDietary calcium intakeIdiopathic infantile hypercalcemiaLikely disease-causing variantsVitamin D metabolitesVitamin D pathwayCalcium homeostatic systemCompound heterozygote mutationsFunction mutationsD supplementationSymptomatic hypercalcemiaCalcium intakeUnrecognized causeVitamin DCalcium metabolismD metabolitesInfantile hypercalcemiaDisease-causing variantsVariant mutationsLoss of functionActive metabolite
2015
Association between serum 25‐hydroxyvitamin D level and pulmonary exacerbations in cystic fibrosis
Vanstone MB, Egan ME, Zhang JH, Carpenter TO. Association between serum 25‐hydroxyvitamin D level and pulmonary exacerbations in cystic fibrosis. Pediatric Pulmonology 2015, 50: 441-446. PMID: 25657016, DOI: 10.1002/ppul.23161.Peer-Reviewed Original ResearchConceptsPulmonary function testsCystic fibrosisPulmonary exacerbationsPediatric patientsD levelsYale-New Haven HospitalPediatric CF patientsVitamin D sufficiencyRetrospective chart reviewVitamin D statusStrongest independent determinantCF care centersPatients ages 5Logistic regression analysisAnnual numberD sufficiencyD statusChart reviewClinic visitsLung functionPulmonary functionAntibiotic therapyFunction testsHospitalization ratesIndependent determinants
2014
Effect of Paricalcitol on Circulating Parathyroid Hormone in X-Linked Hypophosphatemia: A Randomized, Double-Blind, Placebo-Controlled Study
Carpenter TO, Olear EA, Zhang JH, Ellis BK, Simpson CA, Cheng D, Gundberg CM, Insogna KL. Effect of Paricalcitol on Circulating Parathyroid Hormone in X-Linked Hypophosphatemia: A Randomized, Double-Blind, Placebo-Controlled Study. The Journal Of Clinical Endocrinology & Metabolism 2014, 99: 3103-3111. PMID: 25029424, PMCID: PMC4154090, DOI: 10.1210/jc.2014-2017.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAlkaline PhosphataseBone Density Conservation AgentsChildDouble-Blind MethodErgocalciferolsFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsHumansHyperparathyroidismMaleMiddle AgedParathyroid HormonePhosphorusPlacebosProspective StudiesTreatment OutcomeVitamin DYoung AdultConceptsRenal phosphate thresholdGlomerular filtration rateBone scanSerum phosphorusFiltration rateXLH patientsEffect of paricalcitolUse of paricalcitolPlacebo-treated subjectsElevated PTH levelsSerum calcium levelsSuppression of PTHHospital research unitSerum alkaline phosphatase activityPTH levelsCreatinine levelsSecondary outcomesStandard therapyUrinary calciumPlacebo subjectsParathyroid hormoneSerum calciumAlkaline phosphatase activityD levelsSkeletal improvementRandomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia
Carpenter TO, Imel EA, Ruppe MD, Weber TJ, Klausner MA, Wooddell MM, Kawakami T, Ito T, Zhang X, Humphrey J, Insogna KL, Peacock M. Randomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia. Journal Of Clinical Investigation 2014, 124: 1587-1597. PMID: 24569459, PMCID: PMC3973088, DOI: 10.1172/jci72829.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAntibodies, MonoclonalAntibodies, Monoclonal, HumanizedCalciumFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsGlomerular Filtration RateHalf-LifeHumansInjections, IntravenousInjections, SubcutaneousKidney TubulesMaleMiddle AgedPhosphatesVitamin DYoung AdultConceptsTmP/GFRSerum PiParathyroid hormonePhosphate reabsorptionXLH patientsRenal tubular thresholdSerum parathyroid hormoneFavorable safety profileElevated serum FGF23Renal phosphate reabsorptionLow serum concentrationsPhosphate-regulating endopeptidaseSerum Pi concentrationFGF23 antibodySerum FGF23Dihydroxyvitamin DSafety profileTubular thresholdSingle doseSerum concentrationsKRN23Mean t1/2Potential treatmentPatientsEffect durationGastric bypass in obese rats causes bone loss, vitamin D deficiency, metabolic acidosis, and elevated peptide YY
Canales BK, Schafer AL, Shoback DM, Carpenter TO. Gastric bypass in obese rats causes bone loss, vitamin D deficiency, metabolic acidosis, and elevated peptide YY. Surgery For Obesity And Related Diseases 2014, 10: 878-884. PMID: 24969093, PMCID: PMC4113565, DOI: 10.1016/j.soard.2014.01.021.Peer-Reviewed Original ResearchConceptsBone turnover markersDiet-induced obeseWeeks of ageSham surgeryBone lossPeptide YYRYGB animalsBone volumeHigher serum parathyroid hormoneLower trabecular bone volumeMale Sprague-Dawley ratsBone mass differencesElevated peptide YYHigher serum CTXVitamin D malabsorptionSerum parathyroid hormoneGastric bypass surgeryLow serum bicarbonateVitamin D deficiencyNormal calcium dietCortical bone volumeSham control ratsTrabecular bone volumeSprague-Dawley ratsMetabolic bone disease
2012
Vitamin D binding protein is a key determinant of 25‐hydroxyvitamin D levels in infants and toddlers
Carpenter TO, Zhang JH, Parra E, Ellis BK, Simpson C, Lee WM, Balko J, Fu L, Wong B, Cole D. Vitamin D binding protein is a key determinant of 25‐hydroxyvitamin D levels in infants and toddlers. Journal Of Bone And Mineral Research 2012, 28: 213-221. PMID: 22887780, PMCID: PMC3511814, DOI: 10.1002/jbmr.1735.Peer-Reviewed Original ResearchConceptsD binding proteinGC single nucleotide polymorphismsVitamin D binding proteinSingle nucleotide polymorphismsD levelsVitamin D deficiencyVitamin D statusSerum DBP levelsAfrican AmericansD deficiencyD statusCommon single nucleotide polymorphismsNutritional determinantsGC genotypeLarge cohortAIM scoresMultivariate analysisDBP levelsHypercalcemia in Children Receiving Pharmacologic Doses of Vitamin D
Vanstone MB, Oberfield SE, Shader L, Ardeshirpour L, Carpenter TO. Hypercalcemia in Children Receiving Pharmacologic Doses of Vitamin D. Pediatrics 2012, 129: e1060-e1063. PMID: 22412034, PMCID: PMC8194455, DOI: 10.1542/peds.2011-1663.Peer-Reviewed Original ResearchConceptsVitamin DSerum calciumPeak serum calciumResolution of hypercalcemiaWide dosing rangeElevated serum calciumVitamin D deficiencyAge-specific guidelinesAge 2 weeksAdministration of dosagesDaily dietary intakeD deficiencyDeficient ricketsPharmacologic dosesTreatment regimensD levelsHypervitaminosis DDietary intakeDosage recommendationsDose selectionDosing rangeGeneral populationPharmacologic dosingHypercalcemiaSmall childrenEffects of ethnicity and vitamin D supplementation on vitamin D status and changes in bone mineral content in infants
Abrams SA, Hawthorne KM, Rogers SP, Hicks PD, Carpenter TO. Effects of ethnicity and vitamin D supplementation on vitamin D status and changes in bone mineral content in infants. BMC Pediatrics 2012, 12: 6. PMID: 22248486, PMCID: PMC3271033, DOI: 10.1186/1471-2431-12-6.Peer-Reviewed Original ResearchConceptsBone mineral contentBone mineral densityVitamin D supplementationD supplementationVitamin DHispanic infantsDaily vitamin D intakeCaucasian infantsIU/dayVitamin D intakeVitamin D3 supplementationVitamin D statusMonths of lifeNon-Hispanic CaucasiansD intakeD statusD3 supplementationSupplementation interventionsBone healthCord serumMineral densityInfantsFirst monthFirst weekBone mineralization
2011
Demographic, dietary, and biochemical determinants of vitamin D status in inner-city children
Carpenter TO, Herreros F, Zhang JH, Ellis BK, Simpson C, Torrealba-Fox E, Kim GJ, Savoye M, Held NA, Cole D. Demographic, dietary, and biochemical determinants of vitamin D status in inner-city children. American Journal Of Clinical Nutrition 2011, 95: 137-146. PMID: 22170368, PMCID: PMC3238457, DOI: 10.3945/ajcn.111.018721.Peer-Reviewed Original ResearchConceptsParathyroid hormonePmol/LMinority infantsFormula useMeasurement of PTHSkin typeOlder childrenVitamin D insufficientVitamin D intakeVitamin D statusVitamin D fortificationAlkaline phosphatase activityDietary intake dataInner-city childrenClinical ricketsD intakeD statusSerum calciumDihydroxyvitamin DVitamin DD fortificationBlood samplesIntake dataReference rangeTotal alkaline phosphatase activity
2010
Circulating Levels of Soluble Klotho and FGF23 in X-Linked Hypophosphatemia: Circadian Variance, Effects of Treatment, and Relationship to Parathyroid Status
Carpenter TO, Insogna KL, Zhang JH, Ellis B, Nieman S, Simpson C, Olear E, Gundberg CM. Circulating Levels of Soluble Klotho and FGF23 in X-Linked Hypophosphatemia: Circadian Variance, Effects of Treatment, and Relationship to Parathyroid Status. The Journal Of Clinical Endocrinology & Metabolism 2010, 95: e352-e357. PMID: 20685863, PMCID: PMC2968736, DOI: 10.1210/jc.2010-0589.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAge FactorsAgedBone Density Conservation AgentsCalcitriolChildCircadian RhythmEnzyme-Linked Immunosorbent AssayFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsGenetic Diseases, X-LinkedGlucuronidaseHumansKlotho ProteinsMaleMiddle AgedParathyroid HormonePhosphatesVitamin DConceptsSerum KlothoSerum FGF23Higher klotho levelsHospital research unitRenal phosphate handlingAcademic medical centerEffect of treatmentFibroblast growth factorKlotho levelsPTH secretionMedical therapySoluble KlothoDihydroxyvitamin DFGF23 regulationPhosphate handlingMedical CenterFGF23KlothoXLHCircadian variationGrowth factorPTHAdultsHypophosphatemiaTherapy
2007
Evaluation of bone and mineral disorders.
Ardeshirpour L, Cole DE, Carpenter TO. Evaluation of bone and mineral disorders. Pediatric Endocrinology Reviews : PER 2007, 5 Suppl 1: 584-98. PMID: 18167468.Peer-Reviewed Original ResearchConceptsParathyroid hormoneVitamin D homeostasisVitamin D metabolitesEvaluation of boneD homeostasisD metabolitesMineral disordersDiagnostic modalitiesHormonal imbalanceMetabolic diseasesDiagnostic acumenGenetic testingHereditary disorderSkeletal systemHormoneDisordersDiagnostic capabilitiesBoneConcise reviewCalciumWidespread useDiseaseImpairment
2005
Relationships among Vitamin D Levels, Parathyroid Hormone, and Calcium Absorption in Young Adolescents
Abrams SA, Griffin IJ, Hawthorne KM, Gunn SK, Gundberg CM, Carpenter TO. Relationships among Vitamin D Levels, Parathyroid Hormone, and Calcium Absorption in Young Adolescents. The Journal Of Clinical Endocrinology & Metabolism 2005, 90: 5576-5581. PMID: 16076940, PMCID: PMC1283091, DOI: 10.1210/jc.2005-1021.Peer-Reviewed Original ResearchConceptsVitamin D statusCalcium absorptionD statusDihydroxyvitamin DVitamin D insufficiencyVitamin D levelsBone mineral densityCalcium absorption fractionYr of ageEffects of prebioticsD insufficiencySerum PTHPTH secretionD calciumParathyroid hormoneD levelsPediatric dataMineral densityMidpubertal boysYoung adolescentsPTHBone formationWhole bodyHigh rateAdolescentsHypophosphatemia leads to rickets by impairing caspase-mediated apoptosis of hypertrophic chondrocytes
Sabbagh Y, Carpenter TO, Demay MB. Hypophosphatemia leads to rickets by impairing caspase-mediated apoptosis of hypertrophic chondrocytes. Proceedings Of The National Academy Of Sciences Of The United States Of America 2005, 102: 9637-9642. PMID: 15976027, PMCID: PMC1172249, DOI: 10.1073/pnas.0502249102.Peer-Reviewed Original ResearchConceptsParathyroid hormone levelsMineral ion homeostasisRachitic changesHormone levelsAbnormal mineral ion homeostasisDihydroxyvitamin D levelsVitamin D deficiencyDegree of hypophosphatemiaHypertrophic chondrocyte layerVitamin D receptorHypertrophic chondrocytesNormal phosphorus levelsGrowth plate maturationD deficiencyD levelsNormal calciumD receptorChondrocyte layerHypophosphatemiaVDR actionChondrocyte apoptosisNull miceRicketsCaspase-mediated apoptosisHypercalcemia
2002
Variable Degrees of 1-α Hydroxylase Activity—Fine Tuning the Rachitic Rheostat
Carpenter T. Variable Degrees of 1-α Hydroxylase Activity—Fine Tuning the Rachitic Rheostat. The Journal Of Clinical Endocrinology & Metabolism 2002, 87: 2421-2423. PMID: 12050192, DOI: 10.1210/jcem.87.6.8685.Peer-Reviewed Original Research
1989
Mineral regulation of vitamin D metabolism
Carpenter T. Mineral regulation of vitamin D metabolism. Bone And Mineral 1989, 5: 259-269. PMID: 2655775, DOI: 10.1016/0169-6009(89)90004-4.Peer-Reviewed Original ResearchConceptsVitamin D metabolismD metabolismVitamin D deficiencyForms of ricketsD deficiencyVitamin DRenal activityVivo effectsHomeostatic roleIntestinal transportRachitic deformitiesActive metaboliteMineral homeostasisClinical researchMagnesium deficiencyCalcium transportConcentration of calciumMetabolismPediatrician's interestPresent dataStimulationCalciumPhosphorus regulationDeficiencyLesser extent