Background. According to WHO data (2014), more than two billion people are deficient in microelements or have a “hidden hunger” due to the deficiencies of vitamins and minerals. Currently, experts estimate the vitamin D deficiency as a new type of pandemic of the XXI century. Aim. The current analysis was undertaken to evaluate the effect of vitamin D on women’s reproductive health. Materials and Methods. Based on the findings of retrospective and prospective studies, meta-analyzes, and material trials over the past 20 years, as well as in accordance with the results of 290 prospective cohort randomized trials, the level of vitamin D affects 172 basic physiological indicators associated with the risk of such complications of pregnancy as miscarriage, preeclampsia, gestational diabetes mellitus, and bacterial vaginosis. Results. Vitamin D has been shown to be able to act as an immune regulator during the implantation. The placenta produces and responds to vitamin D, which has a local anti-inflammatory response and simultaneously induces the production of decidual growth factors for successful pregnancy. Activated T- and B-lymphocytes have the vitamin D receptors and therefore 1,25(OH)2D is an effective modulator in the immune system. It is able to inhibit the proliferation of Th1 and to restrict the production of such cytokines as interferon-gamma (IFN-γ), interleukin-2 (IL-2), and tumor necrosis factor-alpha (TNF-α). In addition, vitamin D is able to induce cytokines of Th2 that have the protective effect on  pregnancy. Conclusion. Adequate vitamin D intake is important for the successful conception and prolongation of pregnancy, as well as for the health of the fetus and newborn.