To meet this goal we examined: (1) plasma 25OHD and calcium concentrations in control and PCOS rats, (2) 1,25(OH)2D3 concentration in ovarian and POAT homogenates, (3) Vdr, Cyp7b1 and Cyp24a1 mRNA expression, and (4) VDR, CYP27B1 and CYP24A1 proteins abundance, and (5) immunolocalization in the ovary and POAT obtained from control and PCOS rats. Here, CYP27B1 is linked to polycystic ovary syndrome.