title: Vitamin D status in the first-trimester: effects of Vitamin D deficiency on pregnancy outcomes.
abstract: OBJECTIVE
  To assess serum levels of 25-hydroxyvitamin D [25(OH)D] in the first trimester and to determine the factors affecting deficiency levels and its association with pregnancy outcomes.
  
  
  METHODS
  Serum 25(OH)D concentrations were measured at 11-14 weeks' gestation in 229 singleton pregnancies using liquid chromatography-tandem mass spectrometry.
  
  
  RESULTS
  The median serum 25(OH)D concentration was 10.8 ng/mL and 45.9% of women had severe vitamin D deficiency with concentrations of <10 ng/mL. Logistic regression analysis revealed that covered dressing style, lack of multivitamin intake, season of blood sampling (November-April) were factors associated with 25(OH)D deficiency. There was a negative correlation between 25(OH)D levels and gestational age at sampling. Low 25(OH)D levels were not associated with adverse pregnancy outcomes. Higher rate of cesarean section (CS) was noted in women with 25(OH)D ≥10 ng/mL compared to those with 25(OH)D < 10mg/ml (p= 0.01).
  
  
  CONCLUSIONS
  A high prevalence of vitamin D deficiency was observed in early pregnancy which was related to dress code, use of multi-vitamins and season at sampling. Low 25(OH)D levels were not related with adverse pregnancy outcomes. Women with severe vitamin D deficiency were more likely to deliver vaginally.
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors.forename: Seda
authors.initials: S
authors.lastname: Ates
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Sevket
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors.forename: Pinar
authors.initials: P
authors.lastname: Ozcan
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors.forename: Fulya
authors.initials: F
authors.lastname: Ozkal
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Biostatistics and Medical Informatics, Istanbul, Turkey.
authors.forename: Mehmet Onur
authors.initials: MO
authors.lastname: Kaya
authors.affiliation: Bezmialem Vakif University, Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, Turkey.
authors.forename: Banu
authors.initials: B
authors.lastname: Dane
mesh_terms: D000328:Adult; D002853:Chromatography, Liquid; D005260:Female; D006306:Health Surveys; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First / Q000097:blood* / Q000502:physiology; D015995:Prevalence; D012044:Regression Analysis; D012621:Seasons; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry; D014421:Turkey / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D014815:Vitamins / Q000097:blood
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-hydroxyvitamin D; pregnancy outcome; vitamin D deficiency