RESUMO
PROBLEM: The purpose of this study was to explore whether vitamin D might be a marker of female primary infertility in association with the presence of autoimmune diseases (ADs). METHODS: The study was a cross-sectional descriptive study in consecutive outpatients of the Polymedical Center for Prevention of Recurrent Spontaneous Abortion (RSA), in Rome, Italy. Women were eligible if they received a diagnosis of primary infertility or RSA. Serum vitamin D, calcium, and PTH were analyzed. RESULTS: Women with primary infertility (n=70) or RSA/non-infertile (n=105) were enrolled; controls (n=250) were included. Infertile women presented lower vitamin D (P=0.03) and higher prevalence of AD (P=0.007) than non-infertile women. In the multivariate analysis, the presence of ADs is associated with higher odds of infertility (OR=2.2), while normal vitamin D was a protective factor (OR=0.9). CONCLUSION: We described that having vitamin D deficiency and suffering from an AD are independent risk factors for women primary infertility. Supplementation of vitamin D might be useful for pregnancy outcome.