Results of our analyses in kidney stone formers reveal that CYP24A1 activity, estimated by the VMDR, correlates with clinical traits characteristic of idiopathic hypercalciuria after adjustment for multiple confounders, including plasma 25(OH) vitamin D3 and drugs that modulate its concentration, loop and thiazide diuretics, and urinary sodium excretion. This evidence concerns the gene CYP24A1 and nephrolithiasis.