Although hypercalcemia and hyperphosphatemia are the most common side effects of systemic administration of calcitriol, it is generally well tolerated, with other side effects like hypercalciuria and nephrolithiasis occurring in less than 10% of cases [19]. With this in mind, close monitoring of calcium and phosphorus levels is required, with the initiation of phosphorus binders if indicated and consideration of reintroducing cinacalcet if calcium levels become elevated in the setting of high PTH levels [20]. The gene discussed is PTH; the disease is Hypercalciuria.