Objective: The detection of vitamin D3 receptors (VDR) in many tissues in the human body has yielded new insights into the mechanism of vitamin D3. As low levels of vitamin D3 were determined in schizophrenia, bipolar disorder, and depression, vitamin D3 metabolism was suggested as an implicated factor in the underlying mechanism of these disorders. In this study, we aimed to elucidate the metabolism of vitamin D3 in schizophrenia, bipolar disorder, and depression patients.
Methods: In this study 57 schizophrenia, 63 bipolar disorder, and 53 depression patients who were meeting the criteria in DSM-5 and 53 healthy control subjects were enrolled. Vitamin D3 levels were measured in blood samples and compared between all groups.
Results: Significant differences were found in plasma vitamin D levels between all groups by ANOVA statistics (p<0.001). All disease groups are significantly lower than the healthy control group in LSD post-hoc test. Odds ratios are evaluated for comparing disorders by group regarding vitamin D3 (High/Low), which are determined by the median of plasma concentration. Odds ratios were determined; low levels of vitamin D3 were found to be linked to a 6-fold increased risk of schizophrenia, 4-fold increased risk of bipolar disorder, and 5-fold increased risk of depression in patient groups related to healthy controls.
Conclusion: This study indicates that the level of vitamin D3, found to be low in schizophrenia, bipolar disorder, and depression, could be a candidate marker in the diagnosis of these disorders. Whether the status of vitamin D3 deficiency is due to neurodevelopmental processes of the disorders or the sedentary and isolated lifestyle encountered often in these patients is unclear. Future well-established prospective studies are warranted to determinate the role of vitamin D3 in psychiatric disorders and to develop novel promising treatment options.