There is evidence that in addition to the classical sex steroid hormones regulating reproduction, vitamin D also modulates reproductive processes in women and men and its deficiency may impair fertility. In order to evaluate the relationship between low vitamin D status and impaired fertility, a prospective epidemiological study of 458 patients was conducted in the region of Oran (western Algeria). The statistical analysis was performed by SPSS version 25 and Excel software, a P value < 0.05 was accepted as statistically significant. Our study revealed that just 19.2% of our sample had normal vitamin D status and that there was no significant relationship of vitamin D status with age (P>0.05), however the results were significant with body mass indexes (P (χ²) <0.001), and with sex and residence P <0.05. On the other hand our result indicated that as vitamin D status increased, the duration of infertility decreased (P<0.001). The analysis of hormonal profiles showed the presence of a significance between FSH level and vitamin D deficiency (P <0.05). Moreover, we noticed that the vitamin D deficient persons are those who take the supplements (94.44%) for a period not exceeding one month. Whatever the considered field, it is clear that serum vitamin D concentration is a powerful biomarker of an individual's health status. Low concentrations of 25(OH) D are associated with many pathologies including infertility.
