Relationship of serum homocysteine and vitamin D with positive, negative, and extrapyramidal symptoms in schizophrenia: a case–control study in Iran

BACKGROUND: Schizophrenia is a devastating condition characterized by frequent recurrences, cognitive decline, and emotional and functional disabilities. This condition includes positive and negative symptoms and cognitive impairments resistant to drug treatment. According to studies, many biomarkers can affect this disorder. However, there is little information about vitamin D and homocysteine levels in patients with disease complications. We aimed to investigate this relationship in schizophrenia. METHOD: In this case–control study, 33 patients with schizophrenia and 33 healthy individuals were enrolled from Golestan, the north of Iran, in 2021. Blood samples were taken from all participants to assess vitamin D and homocysteine serum levels. In addition, schizophrenic patients completed the Positive And Negative Syndrome Scale (PANSS) and Simpson-Angus Extrapyramidal Side Effects Scale (SAS). Data analysis was performed at a significance level of 0.05 using SPSS 16 software. RESULTS: Of the 66 participants, 66.7% had vitamin D deficiency, and 71.2% had normal homocysteine levels. However, the serum level of vitamin D was lower in schizophrenic patients than in controls (p = 0.035), and serum homocysteine levels were higher in the schizophrenic group than in controls (p < 0.001). Vitamin D levels in patients with schizophrenia were significantly correlated with the overall assessment of extrapyramidal symptoms (r = 0.35, p = 0.04). However, no significant relationship existed between vitamin D and homocysteine levels and PANSS results (p > 0.05). CONCLUSION: Serum levels of vitamin D and homocysteine were significantly lower and higher in schizophrenic patients than in the control group. Improvement of extrapyramidal symptoms in schizophrenic patients had a direct and significant relationship with serum vitamin D.