Abstract
Background
Low levels of vitamin D are prevalent among patients with schizophrenia and previously had been linked to the risk and outcome of the disorder. While vitamin D has a regulatory effect on the inflammatory system, schizophrenia had also been associated with inflammatory dysregulation. Therefore, we investigated the association between vitamin D level, inflammatory status, and severity of schizophrenia symptoms.
Methods
A sample of 39 chronic clozapine-treated patients with schizophrenia had been recruited to the study. Each patient went through a clinical assessment and gave a blood sample for biochemical analysis. Serum levels of vitamin D and cytokines (IL-4, IL-6, IL-10, and TNF-α) were analyzed for correlation between variables as well as with clinical severity measures.
Results
Most of the sample (82%) had non-satisfactory levels of vitamin D. There was a significant negative association between vitamin D levels and IL-6 (Pearson’s r=-0.38, p<0.050. Vitamin D levels and positive symptoms severity were positively correlated (r=0.39, p<0.05).
Discussion
The results of this study suggest an anti-inflammatory effect of vitamin D in a sample of chronic clozapine-treated schizophrenia patients. This effect may mediate the association between low levels of vitamin D and risk for schizophrenia.