Assessment of serum vitamin D levels in patients with major depressive disorder. Single-center case-control study.

Objective: Depression has a complex etiopathogenesis and represents a significant worldwide health burden. The precise relationship between serum vitamin D and depression remains debated. The purpose of the current study was to investigate whether vitamin D has a role in the development of depression and/or the severity of depressive symptoms. Methods: This prospective single-center case-control study assessed serum vitamin D levels in fifty consecutive patients diagnosed with major depressive disorder (MDD) using the Structured Clinical Interview for DSM-IV (SCID-I). Similarly, an age- and sex- matched control group of fifty healthy individuals was recruited from relatives and acquaintances of patients attending the outpatient psychiatric clinic at Minia University Hospital, Egypt. Results: The study included 50 patients diagnosed with major depressive disorder (MDD) and 50 matched controls with no significant demographic differences between groups. Although vitamin D deficiency was more prevalent in the control group (60% vs. 30% of patients), the severity of depression showed a significant positive correlation with low vitamin D levels (P = 0.02). Conclusion: There were associations between the level of vitamin D and depressive disorders, including the severity of illness. However, further research studies are needed to validate its correlation to the etiopathogenesis of depression.