FGF23 and Marchiafava-Bignami disease: Therefore, to further identify CKD-MBD-related parameters independently associated with serum f(HNA), we performed additional multivariate analyses with the parameters corrected calcium, phosphate, intact-PTH, FGF-23, and 1,25-dihydroxyvitamin D (1,25(OH)2D) included as explanatory variables.