Abstract
BACKGROUND: Bipolar disorder is a chronic psychiatric disorder with depression and manic episodes. It is one of the leading causes of disease-related disability worldwide. Despite the presence of various alternative drug options for bipolar disorder, some patients do not adequately benefit from the treatment. Therefore, possible underlying mechanisms need to be clarified. Recently, studies on the relationship between bipolar disorder and vitamin D (Vit D) have attracted attention. Although many studies have found an association between depression and Vit D deficiency, little is known about the relationship between manic episodes and Vit D. The aim of this study was to compare Vit D and related metabolites of bipolar manic episodes prior to treatment, bipolar remission after treatment, and healthy control groups. METHODS: This case-control study consisted of 34 bipolar manic episode patients and 34 healthy controls. Disease activity was evaluated with the Hamilton Depression Rating Scale (HAM-D) and Young Mania Rating Scale (YMRS). Firstly, serum 25-hydroxy vitamin D (25-OHD), calcium (Ca) and phosphorus (P) levels of patients in the bipolar manic episode were measured and compared with healthy control. Secondly, serum 25-OHD, Ca and P levels in the euthymic periods of the same patients were measured and compared with healthy control. RESULTS: Bipolar manic episode Vit D levels were lower when compared to healthy controls; while there was no difference in terms of Ca and P levels. There was no significant difference between the bipolar euthymic period patients and the healthy control group in terms of 25-OHD, Ca and P levels. CONCLUSION: Our results demonstrated low serum Vit D concentrations in the acute manic episode of bipolar disorder. Decreased Vit D level may play a role in the onset of the manic episode, or malnutrition and insufficient sunlight during the manic episode may have caused Vit D deficiency. Future studies are needed to exclude potential confounding factors and to compare all mood episodes.