title: Predicted vitamin D status during pregnancy in relation to offspring forearm fractures in childhood: a study from the Danish National Birth Cohort.
abstract: In a prospective cohort study, the association between maternal vitamin D status during pregnancy and offspring forearm fractures during childhood and adolescence was analysed in 30 132 mother and child pairs recruited to the Danish National Birth Cohort between 1996 and 2002. Data on characteristics, dietary factors and lifestyle factors were collected on several occasions during pregnancy. We analysed the association between predicted vitamin D status, based on a subsample with 25-hydroxyvitamin D (25(OH)D) biomarker measurements (n 1497) from gestation week 25, and first-time forearm fractures among offspring between birth and end of follow-up. Diagnoses were extracted from the Danish National Patient Register. Multivariable Cox regression models using age as the underlying time scale indicated no overall association between predicted vitamin D status (based on smoking, season, dietary and supplementary vitamin D intake, tanning bed use and outdoor physical activity) in pregnancy and offspring forearm fractures. Likewise, measured 25(OH)D, tanning bed use and dietary vitamin D intake were not associated with offspring forearm fractures. In mid-pregnancy, 91 % of the women reported intake of vitamin D from dietary supplements. Offspring of women who took >10 µg/d in mid-pregnancy had a significantly increased risk for fractures compared with the reference level of zero intake (hazard ratios (HR) 1·31; 95% CI 1·06, 1·62), but this was solely among girls (HR 1·48; 95% CI 1·10, 2·00). Supplement use in the peri-conceptional period exhibited similar pattern, although not statistically significant. In conclusion, our data indicated no protective effect of maternal vitamin D status with respect to offspring forearm fractures.
authors.affiliation: 1Department of Epidemiology Research,Centre for Fetal Programming,Statens Serum Institut,DK-2300 Copenhagen S,Denmark.
authors.forename: Sesilje B
authors.initials: SB
authors.lastname: Petersen
authors.affiliation: 1Department of Epidemiology Research,Centre for Fetal Programming,Statens Serum Institut,DK-2300 Copenhagen S,Denmark.
authors.forename: Marin
authors.initials: M
authors.lastname: Strøm
authors.affiliation: 1Department of Epidemiology Research,Centre for Fetal Programming,Statens Serum Institut,DK-2300 Copenhagen S,Denmark.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Maslova
authors.affiliation: 1Department of Epidemiology Research,Centre for Fetal Programming,Statens Serum Institut,DK-2300 Copenhagen S,Denmark.
authors.forename: Charlotta
authors.initials: C
authors.lastname: Granström
authors.affiliation: 2Department of Endocrinology,Aalborg University Hospital,DK-9000 Aalborg,Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Vestergaard
authors.affiliation: 4Department of Nutrition,Exercise and Sports, Faculty of Science,University of Copenhagen,DK-1958 Frederiksberg C,Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Mølgaard
authors.affiliation: 1Department of Epidemiology Research,Centre for Fetal Programming,Statens Serum Institut,DK-2300 Copenhagen S,Denmark.
authors.forename: Sjurdur F
authors.initials: SF
authors.lastname: Olsen
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002112:Calcifediol / Q000097:blood; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D047109:Fetal Development; D005500:Follow-Up Studies; D005542:Forearm; D050723:Fractures, Bone / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D009752:Nutritional Status; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000503:physiopathology*; D011263:Pregnancy Trimester, Third; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012042:Registries; D012306:Risk; D014808:Vitamin D Deficiency / Q000097:blood / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol
keywords: 25(OH)D 25-hydroxyvitamin D; DNBC Danish National Birth Cohort; Epidemiology; Fetal programming; Fractures; HR hazard ratio; Pregnancy; Vitamin D