Vitamin D Deficiency in Adult Patients with Schizophreniform and Autism Spectrum Syndromes: A One-Year Cohort Study at a German Tertiary Care Hospital

Abstract

Introduction: 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.

Participants and 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.

Discussion: 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.

Keywords: autism spectrum disorder; inflammation; mild encephalitis; schizophrenia; vitamin D.

Figure 1

Vitamin D level distribution over 1 year among the schizophreniform and autism spectrum disorder groups. Five patients reached recommended levels >30 ng/ml: patient 1: 43 years, female, schizophreniform syndrome (organic schizophreniform disorder), treated with olanzapine, body mass index (BMI) of 26.7 kg/m²; patient 2: 25 years, male, autism spectrum disorder (Asperger syndrome), no psychiatric medication, BMI of 19.4 kg/m²; patient 3: 41 years, male, autism spectrum disorder (atypical autism), treated with olanzapine and clomipramine, BMI of 23.7 kg/m²; patient 4: 37 years, male, schizophreniform syndrome (schizophrenia), treated with olanzapine and escitalopram, BMI of 25.6 kg/m²; patient 5: 21 years, male, schizophreniform syndrome (schizoaffective disorder), treated with quetiapine and venlafaxine, BMI of 26.4 kg/m².