title: A cross-sectional study of vitamin D deficiency among immigrants and Norwegians with psychosis compared to the general population.
abstract: OBJECTIVE
  Vitamin D deficiency is common among immigrants, who, as a group, have heightened risk of psychosis. This study aimed to determine vitamin D levels among immigrants and Norwegians with psychosis compared to the general population and their association to clinical characteristics.
  
  
  METHODS
  This study compared vitamin D levels between immigrants and Norwegians within and between samples of patients with psychosis from a catchment area-based cross-sectional study (2002-2007) with a sample from a population-based health study from the same catchment area (2000-2001). The psychosis sample included patients with a Structured Clinical Interview for DSM-IV Axis I Disorders diagnosis of psychotic disorder (67 immigrants, 66 Norwegians). The reference sample consisted of 1,046 subjects (177 immigrants, 869 Norwegians). Serum levels of vitamin D were measured by radioimmunoassay, and results were presented as 25-hydroxyvitamin D levels.
  
  
  RESULTS
  Over 80% (n = 55) of immigrant patients with psychosis had insufficient/deficient serum levels of 25-hydroxyvitamin D (< 50 nmol/L). Immigrants had higher rates of 25-hydroxyvitamin D deficiency than Norwegians (P < .001). Norwegians with psychosis had lower serum levels of 25-hydroxyvitamin D than Norwegians in the reference sample from the general public (P < .001). 25-hydroxyvitamin D levels correlated with certain negative/depressive symptoms among patients with psychosis.
  
  
  CONCLUSIONS
  An alarmingly high percentage of immigrants and Norwegians with psychotic disorders have 25-hydroxyvitamin D deficiency. This has important clinical implications as it suggests possible beneficial effects of vitamin D medication/heliotherapy within this group.
authors.affiliation: Institute of Psychiatry, University of Oslo, Oslo University Hospital, Building 49, Kirkeveien 166, N-0407 Oslo, Norway. a.o.berg@medisin.uio.no
authors.forename: Akiah Ottesen
authors.initials: AO
authors.lastname: Berg
authors.forename: Ingrid
authors.initials: I
authors.lastname: Melle
authors.forename: Peter A
authors.initials: PA
authors.lastname: Torjesen
authors.forename: Lars
authors.initials: L
authors.lastname: Lien
authors.forename: Edvard
authors.initials: E
authors.lastname: Hauff
authors.forename: Ole A
authors.initials: OA
authors.lastname: Andreassen
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D054242:Emigrants and Immigrants / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology / Q000208:ethnology; D011618:Psychotic Disorders / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology*; D011863:Radioimmunoassay; D012494:Sampling Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000208:ethnology* / Q000523:psychology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D