Nevertheless, for severe UHPT, previous studies highlighted that active vitamin D analogs, especially non-selective VDR activator calcitriol, had the potential to raise serum calcium and phosphorus levels, which are accompanied with increased risk for cardiovascular disease mediated through probable vascular calcification by enhancing gastrointestinal absorption of calcium and phosphate [7,8,13,22], thereby limiting its efficacy due to frequent interruption of its usage. This evidence concerns the gene VDR and calcification.