DBP and chronic kidney disease: The present data also indicate a positive association of urinary C-megalin excretion with log[1,25(OH)2D/25(OH)D] and log[1,25(OH)2D/24,25(OH)2D], which may be caused by reduced megalin-mediated uptake of 25(OH)D-DBP complexes and altered trafficking of 25(OH)D to mitochondria sites, where 1α(OH)ase and 24(OH)ase co-exist17, due to phenotypic changes in PTECs under conditions associated with CKD.