Falecalcitriol is a synthetic vitamin D analog primarily used in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD), particularly those on dialysis. It regulates calcium and phosphate levels by enhancing intestinal calcium absorption, suppressing parathyroid hormone (PTH) secretion, and modulating bone metabolism. This helps prevent renal osteodystrophy, vascular calcification, and other mineral bone disorders associated with CKD. It is also indicated for osteoporosis management, where it improves bone mineral density and reduces fracture risk. Due to its potent activity, careful monitoring for hypercalcemia and hyperphosphatemia is essential.