Turan G.A.Eskicioglu F.Sivrikoz O.N.Cengiz H.Gur E.B.Tatar S.Sahin N.Yilmaz O.2025-04-102025-04-102015http://hdl.handle.net/20.500.14701/49034Purpose: To investigate the effect of vitamin D in ovarian hyperstimulation syndrome (OHSS). Methods: In this animal study, 28 immature female Wistar rats were divided into four groups: group 1 (control); group 2 (ovarian stimulation); group 3 (OHSS group); group 4 (OHSS + vitamin D group). All groups were killed 48 h after hCG administration and were compared in terms of vascular permeability, ovarian weight, ovarian diameter, vascular endothelial growth factor (VEGF) expression (immunohistochemistry) in ovarian tissue and pigment epithelium-derived factor (PEDF) level in the serum (ELISA test) with the Kruskal–Wallis and Mann–Whitney U tests. Results: VEGF expression in the vitamin D group was similar to that in the OHSS group. However, the PEDF level was significantly higher in the vitamin D group (p = 0.013). Conclusions: Prophylactic vitamin D supplementation is not sufficiently effective in preventing OHSS. Vitamin D effectively increases PEDF, which has an opposing effect on VEGF, which plays a key role in OHSS. Thus, the protective effect of Vitamin D on OHSS should be investigated with a vitamin D deficient model in the study group. © 2015, Springer-Verlag Berlin Heidelberg.Article10.1007/s00404-015-3625-1