• deficiency
• inflammation
• obsessive-compulsive disorder
• platelets
• vitamin D

Introduction. Previous studies have indicated that vitamin D deficiency is common in psychiatric patients, particularly in those with neuropsychiatric disorders such as autism and schizophrenia. Vitamin D is an important neurosteroid hormone and immunomodulatory agent that also has bone metabolic effects. There has been an increasing interest in order to define the possible role of Vitamin D in the etiology of several neuropsychiatric disorder. In this study, we aimed to study the Vitamin D levels in patients with a diagnosis of obsessive-compulsive disorder (OCD) and to correlate these values to the psychopathological severity degree of the illness.
Methods and Materials. Thirty OCD patients were enrolled in the study and serum 25-hydroxyvitamin D (25-(OH) D) values were analyzed. Values < 12 nm/L were classified as vitamin D critical deficiency, values comprised between 12 and 20 as insufficient, > 20 but lower than 30 as sufficient. The Yale-Brown Obsessive-Compulsive Scale (YBOCS) was used to assess the severity of OCD symptoms.
Results. Compared to the upper normality limit of the Vitamin D level of the Mediterranean population, our sample presented statistically significant lower values. There were no significant correlations with Vitamin D levels, age of onset and duration of illness, and there was not gender differences. However, after having stratified the sample by age, the older quartile had Vitamin D levels inversely correlated with Interference of Obsessions on Life, Distress degree caused by compulsion, pervasive slowness and Y-BOCS total score. Surprisingly, in our sample the mean age value of the sample did not correlate with Vitamin D levels and Y-BOCS total score.
Conclusion. In light of these findings and taking into account the limitations of the present study, we offer promising data that support the hypothesis of neurobiological effects of vitamin D on central nervous system, or a possible association between central vitamin D and OCD. However, there is a need for prospective studies addressing to a better understanding of this supposed relationship also in order to propose some possible useful clinical therapeutic implications.