Zemplar, generically known as paricalcitol, is a synthetic vitamin D analog prescribed to prevent and treat secondary hyperparathyroidism (increased parathyroid hormone levels) in patients with chronic kidney disease (CKD) on dialysis. Secondary hyperparathyroidism is a common complication of CKD, characterized by an imbalance in calcium and phosphorus levels in the body, leading to increased parathyroid hormone production. Zemplar works by inhibiting parathyroid hormone secretion, helping to maintain balanced levels of calcium and phosphorus, and supporting bone health. It is available in both oral and injectable forms, allowing for flexibility in administration based on patient needs and preferences. As with any medication, it is important to use Zemplar under the guidance of a healthcare professional to ensure proper dosing and to monitor for potential side effects.