FGF23 and autosomal dominant polycystic kidney disease: Median FGF-23 in the whole sample, composed mostly of ADPKD patients at CKD stages 1 and 2, was high if compared to CKD caused by other conditions (49, 50), being in agreement with Pavik et al. (51) who observed a four-fold increase in FGF-23 from ADPKD compared to CKD of other etiologies with similar eGFR, although no association with 25(OH) and 1,25 (OH)2D was detected.