title: Associations between serum 25-hydroxyvitamin D and bone turnover markers in a population based sample of German children.
abstract: Severe vitamin D deficiency is known to cause rickets, however epidemiological studies and RCTs did not reveal conclusive associations for other parameters of bone health. In our study, we aimed to investigate the association between serum levels of 25(OH) vitamin D and bone turnover markers in a population-based sample of children. 25(OH)D, calcium (Ca), osteocalcin (OC), and β-Crosslaps (β-CTx) were measured in 2798 ten-year-old children from the German birth cohorts GINIplus and LISAplus. Linear regression was used to determine the association between bone turnover markers and 25(OH)D levels. 25(OH)D, OC, and β-CTx showed a clear seasonal variation. A 10 nmol/l increase in 25(OH)D was significantly associated with a 10.5 ng/l decrease (p < 0.001) in β-CTx after adjustment for design, sex, fasting status, time of blood drawn, BMI, growth rate, and detectable testosterone/estradiol. For OC alone no significant association with 25(OH)D was observed, whereas the β-CTx-to-OC ratio was inversely associated with 25(OH)D (-1.7% change, p < 0.001). When stratifying the analyses by serum calcium levels, associations were stronger in children with Ca levels below the median. This study in school-aged children showed a seasonal variation of 25(OH)D and the bone turnover markers OC and β-CTx. Furthermore a negative association between 25(OH)D and the bone resorption marker β-CTx was observed.
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München- German Research Center for Environmental Health, Neuherberg, Germany.|Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children's Hospital, University of Munich Medical Center, Munich, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Thiering
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München- German Research Center for Environmental Health, Neuherberg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Brüske
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kratzsch
authors.affiliation: Division of Endocrinology, Diabetes, and Bone Diseases, Dresden Technical University Medical Center, Dresden, Germany.
authors.forename: L C
authors.initials: LC
authors.lastname: Hofbauer
authors.affiliation: Research Institute, Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Berdel
authors.affiliation: Research Institute, Department of Pediatrics, Marien-Hospital Wesel, Wesel, Germany.
authors.forename: A
authors.initials: A
authors.lastname: von Berg
authors.affiliation: Department of Environmental Immunology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Lehmann
authors.affiliation: Medical School, the Heinrich Heine University of Düsseldorf, Düsseldorf, Germany and IUF Leibniz Research Institute for Environmental Medicine at the University of Düsseldorf, Düsseldorf, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hoffmann
authors.affiliation: Department of Pediatrics, Technical University of Munich, Munich, Germany.
authors.forename: C P
authors.initials: CP
authors.lastname: Bauer
authors.affiliation: Division of Pediatric Gastroenterology and Hepatology, Dr. von Hauner Children's Hospital, University of Munich Medical Center, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Koletzko
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München- German Research Center for Environmental Health, Neuherberg, Germany.|Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, University Hospital Munich, Ludwig Maximilians University Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Heinrich
mesh_terms: D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D016723:Bone Remodeling; D001862:Bone Resorption / Q000097:blood; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000097:blood; D002648:Child; D015331:Cohort Studies; D024042:Collagen Type I / Q000097:blood; D005215:Fasting / Q000097:blood; D005260:Female; D005858:Germany; D006801:Humans; D016014:Linear Models; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000097:blood; D011159:Population Surveillance / Q000379:methods; D012621:Seasons; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium