calcifediol + paricalcitol

Calcifediol + paricalcitol is a combination of two active forms of vitamin D analogs, administered together for the management of secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease, particularly those on hemodialysis. Calcifediol (25-hydroxyvitamin D) is a prehormone that is converted in the kidney to the active form, exerting effects primarily by increasing serum levels of 25(OH)D. Paricalcitol is a synthetic selective vitamin D receptor activator (VDRA) that suppresses parathyroid hormone (PTH) synthesis and release by binding to and activating the vitamin D receptor, with reduced activity at increasing calcium and phosphate compared to calcitriol. The combination has been studied for its impact on bone-mineral metabolism and cardiovascular risk markers. Clinical evidence suggests that co-administration does not provide a marked advantage over individual monotherapy in reducing PTH or inflammatory markers.