Ghazaleh Valipour, from the Isfahan University of Medical Sciences in Iran, and colleagues conducted a systematic review and meta-analyses to examine the correlation between serum vitamin D levels and schizophrenia. Nineteen studies were included in three meta-analyses relating to the mean levels of serum hydroxyvitamin D (25[OH]D; 13 studies), the prevalence of vitamin D deficiency (eight studies), and odds ratios for schizophrenia (eight studies).
The researchers observed an overall mean difference of −5.91ng/mL in serum 25(OH)D levels between patients with schizophrenia and control participants. Between-study heterogeneity was not associated with hospitalization status, study quality, and study location, but was partially explained by type of biomarker assessed. The overall prevalence of vitamin D deficiency was 65.3% in patients with schizophrenia. Compared with individuals with vitamin D sufficiency, those with vitamin D deficiency were 2.16-fold more likely to have schizophrenia, with no indication of heterogeneity.
“We found a strong association between vitamin D deficiency and schizophrenia. However, randomized clinical trials are required to confirm our findings,” the authors write.