Is there a Relationship between Vitamin D and Endometriosis? An Overview of the Literature

Background: Vitamin D is involved in the physiological functions of several tissues, however, its deficiency may contribute to the development of various disorders. Recent research has been focusing on the role of vitamin D in the pathogenesis of endometriosis based on the evidence of the presence of vitamin D receptor and the enzymes required for vitamin D synthesis in the ectopic endometrium. Endometriosis, defined as the presence of endometrial glands and stroma in ectopic locations, is considered an estrogen-dependent disease and Vitamin D seems to have a role in modulation of the inflammatory state and proliferation of endometriotic cells. Objective: This study aimed to review the available literature regarding the relationship between vitamin D and endometriosis as well as the effects of vitamin D supplementation. Methods: A search on PubMed database has been performed. Results: The relationship between endometriosis and Vitamin D has been analyzed through the evaluation of vitamin D serum level, the polymorphism of vitamin D receptor and the role of vitamin D-binding protein in patient with endometriosis. The possible role of Vitamin D in the endometriosis therapy has also been investigated, in particular, the effect of vitamin D on pain relief, on endometriotic lesion in vitro and in rat models and in addition to a future target immunotherapy. Conclusion: Although promising, the data analyzed are not sufficient to evidence a cause-effect relationship between VD status and endometriosis, therefore further studies are needed in order to better clarify the association between vitamin D and endometriosis, especially in the context of the possibility of new treatment options.