Low levels of 25-OH vitamin D in women with endometriosis and associated pelvic pain

Introduction: Endometriosis is a chronic disease often associated with pelvic pain and infertility. It has been shown that vitamin D plays an important role in the physiological functions of the reproductive system. Conflicting data have been reported on the relationship between endometriosis and vitamin D. The aim of the present prospective observational cohort study was to analyze the correlation between the levels of 25-OH Vitamin D and endometriosis and associated symptoms. Materials and methods: 25-OH Vitamin D serum levels (normal value ≥ 30 ng/ mL) have been analyzed in 104 women with surgically confirmed endometriosis. Pain symptoms, fertility and CA125 values of all patients were evaluated and recorded. Intensity of pain was measured by the means of 10- points Visual Analogue Scale (VAS). Correlation between vitamin D levels and presence of endometriosis, pain, infertility and CA125 levels was analyzed. Results: Insufficient 25-OH Vitamin D levels were found in 80% of women with endometriosis; this association was statistically significant (p<0.001). Low levels also correlated with the presence of moderate/ severe pain ≥ 5 VAS score (p< 0.02) and high levels of CA125 (p< 0.03). No correlation was found with infertility and other evaluated factors. Conclusions: The results of this study highlight the role of 25-OH Vitamin D as a possible modifiable risk factor for endometriosis and its symptoms, although a cause-effect relationship is not clear. Further studies are needed to confirm this association. Vitamin D supplementation could be suggested in selected patients with insufficiency of the vitamin associated with symptomatic endometriosis