CYP24A1 and Hypercalciuria: Recent evidence has identified loss of function mutations in CYP24A1, encoding the vitamin D-24-hydroxylase which regulates the catabolism of 1,25(OH)2D, can result in high circulating levels of 1,25(OH)2D, hypercalcemia, hypercalciuria, and nephrolithiasis in humans [50].