Doxercalciferol is primarily used in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease who are undergoing dialysis. It helps to regulate calcium and phosphorus levels in the blood by suppressing the secretion of parathyroid hormone, which can become elevated in kidney disease. This action helps to prevent bone disease and other complications associated with abnormal mineral metabolism. Additionally, doxercalciferol is sometimes used in the management of vitamin D deficiency in patients who cannot adequately convert vitamin D to its active form. Its use is carefully monitored to avoid potential side effects such as hypercalcemia or hyperphosphatemia.