title: Maternal vitamin D deficiency and the risk of autism spectrum disorders: population-based study.
abstract: BACKGROUND
  Maternal vitamin D deficiency may increase risk of autism spectrum disorder (ASD), but direct evidence is lacking.
  
  
  OBJECTIVE
  To clarify the relationship between maternal vitamin D deficiency and offspring risk of ASD with and without intellectual disability.
  
  
  METHODS
  Using a register-based total population study (N=509 639), we calculated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of ASD with and without intellectual disability in relation to lifetime diagnoses of maternal vitamin D deficiency. Although rare, such deficiency was associated with offspring risk of ASD with, but not without, intellectual disability (aORs 2.51, 95% CI 1.22-5.16 and 1.28, 0.68-2.42). Relationships were stronger in non-immigrant children.
  
  
  CONCLUSIONS
  If reflecting associations for prenatal hypovitaminosis, these findings imply gestational vitamin D substitution as a means of ASD prevention.
  
  
  BACKGROUND
  None.
  © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.
authors.affiliation: , MD, PhD.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Magnusson
authors.affiliation: , MPH, Department of Public Health Sciences, KarolinskaInstitutet, Stockholm, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Lundberg
authors.affiliation: , PhD, Department of Epidemiology and Biostatistics, A.J. Drexel Autism Institute, Drexel University School of Public Health, Philadelphia, PA, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Lee
authors.affiliation: , MRCPsych, PhD, Department of Public Health Sciences, KarolinskaInstitutet, Stockholm, Sweden; Centre for Academic Mental Health, School of Social and Community Medicine, University of Bristol, Bristol, UK; Avon and Wiltshire Partnership Mental Health NHS Trust, Bristol, UK.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Rai
authors.affiliation: , PhD, Department of Neuroscience, KarolinskaInstitutet, Stockholm, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Karlsson
authors.affiliation: , PhD, Department of Public Health Sciences, KarolinskaInstitutet, Stockholm, Sweden.
authors.forename: Renee
authors.initials: R
authors.lastname: Gardner
authors.affiliation: , MD, PhD.
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Kosidou
authors.affiliation: , MD, PhD, Department of Medicine, KarolinskaInstitutet, Stockholm, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Arver
authors.affiliation: , MD, PhD, Department of Public Health Sciences, KarolinskaInstitutet, Stockholm, Sweden; Centre for Epidemiology and Community Medicine, Stockholm County Council, Solna, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Dalman