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. The gene discussed is CYP24A1; the disease is polycystic ovary syndrome.