CALB1 and Hypercalciuria: Further evidence supporting biologic actions of high 1,25-vitamin D included changes in renal Cyp24a1, Trpv5, and Calbindin D28k expression (Figure 5, J and K); circulating intact and C-terminal FGF23 levels (Supplemental Figure 6, W and X); and hypercalciuria (Figure 5L).