Vitamin D Levels and Vitamin D Receptor Gene Polymorphism in Major Depression

The aim of this study is to evaluate vitamin D levels and rs2228570 (FokI) polymorphism of vitamin D in patients with established diagnosis of major depressive disorder in order to investigate the impact of vitamin D levels and genetic polymorphisms on etiology and/or severity of the disease. The study included 86 patients who were diagnosed with major depressive disorder in Hospital of Balıkesir University Faculty of Medicine, Department of Psychiatry, and 89 healthy volunteers with similar age, sex, education level and BMI. Psychiatric diagnosis was established by using Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). For clinical evaluation, sociodemographic data form, Hamilton Depression Rating Scale, Hamilton Anxiety Scale were used. Blood samples were drawn after 12 hours of fasting from the patients volunteered and the control group who were given their informed consent for participation in the study. Vitamin D levels were determined by using the method of ECLIA (Electrochemiluminescent immunoassay). Genotype analysis was performed using the method of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). In our study, median vitamin D levels (min-max) of the patient and control groups were 10.3 ng/mL (3.0-42.1) and 11.4 ng/mL (3.0-38.8), respectively. Statistically significant differences as for vitamin D levels between groups were not detected (p=0.729). Similiarly no statistically significant difference between groups in genotype distribution was observed (p=0.396). In conclusion, our findings do not support the relationship between depression, vitamin D levels and Fok 1 polymorphism of vitamin D receptor. To test these hypotheses in the light of literature we need further studies to be performed with large number of patients.