Our study demonstrated an independent association between serum 1,25(OH)2D and cardiac valve calcification even after adjustment for several confounding factors of CKD-MBD (calcium, phosphate, Ca × P product, and intact PTH levels), suggesting a direct causal role of low serum 1,25(OH)2D levels in cardiac valve calcification in patients with CKD. This evidence concerns the gene PTH and Marchiafava-Bignami disease.