title: Vitamin D Deficiency in Adult Patients with Schizophreniform and Autism Spectrum Syndromes: A One-Year Cohort Study at a German Tertiary Care Hospital.
abstract: BACKGROUND
  Vitamin D has many immunomodulatory, anti-inflammatory, and neuroprotective functions, and previous studies have demonstrated an association between vitamin D deficiency and neuropsychiatric disease. The aim of our study was to analyze the prevalence of vitamin D deficiency in a 1-year cohort of adult inpatients with schizophreniform and autism spectrum syndromes in a naturalistic inpatient setting in Germany.
  
  
  METHODS
  Our study was comprised of 60 adult schizophreniform and 23 adult high-functioning autism spectrum patients who were hospitalized between January and December of 2015. We compared our findings with a historical German reference cohort of 3,917 adults using Pearson's two-sided chi-squared test. The laboratory measurements of 25-hydroxyvitamin D2/3 [25(OH)vitamin D] were obtained using a chemiluminescence immunoassay.
  
  
  RESULTS
  In the schizophreniform group, we found decreased (<20 ng/ml) 25(OH)vitamin D levels in 48/60 (80.0%) of the patients. In the autism spectrum group, decreased levels were detected in 18/23 (78.3%) of the patients. 25(OH)vitamin D deficiencies were found in 57.3% of the historical control group. Particularly, severe deficiencies (<10 ng/ml) occurred much more frequently in the schizophreniform (38.3%) and autism spectrum groups (52.2%), when compared to the control group (16.3%). The recommended 25(OH)vitamin D values of >30 ng/ml were observed in only 5% of the schizophreniform patients, 8.7% of the autism spectrum patients, and 21.9% of the healthy controls.
  
  
  CONCLUSIONS
  We found very high rates of 25(OH)vitamin D deficiencies in both patient groups and have discussed whether our findings might be related to alterations in the immunological mechanisms. Irrespective of the possible pathophysiological links between vitamin D deficiency and schizophrenia or autism spectrum disorders, a more frequent measurement of vitamin D levels seems to be justified in these patient groups. Further prospective, controlled, blinded, and randomized research should be conducted to analyze the effectiveness of vitamin D supplementation on the improvement of psychiatric symptoms.
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Dominique
authors.initials: D
authors.lastname: Endres
authors.affiliation: Department of Neurology, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Rick
authors.initials: R
authors.lastname: Dersch
authors.affiliation: Department of Neurology, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Stich
authors.affiliation: Institute for Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Buchwald
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Evgeniy
authors.initials: E
authors.lastname: Perlov
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Feige
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Maier
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Riedel
authors.affiliation: Section of Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg , Freiburg , Germany.
authors.forename: Ludger Tebartz
authors.initials: LT
authors.lastname: van Elst
keywords: autism spectrum disorder; inflammation; mild encephalitis; schizophrenia; vitamin D