FGF23 and chronic kidney disease: Firstly, in the present study, data for several CKD-related parameters not included in the previous study13 have been added, including eGFR, urinary protein, sodium-chloride, TSAT, use of ESA or iron supplementation, intact-PTH, FGF-23, 1,25(OH)2D, plasma glucose, and hemoglobin A1c.