[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C@H1][Branch1][=Branch2][C][C][C][C][Branch1][C][C][C][C@H1][C][C][C@@H1][C@@][Ring1][Branch1][Branch2][Ring1][Branch2][C][C][C][/C][\\-Ring1][=Branch1][=C][\\C][=C][\\C][C@H1][Branch1][#Branch2][C][C@@H1][Branch1][Branch1][C][/-Ring1][=Branch1][=C][O][O][C]"}, {"from": "gpt", "value": "The molecule is a non-endogenous analogue of [vitamin D]. It plays an essential function in calcium homeostasis and bone metabolism. Alfacaldisol is activated by the enzyme 25-hydroxylase in the liver to mediate its effects in the body, or most importantly, the kidneys and bones. The pharmacological actions of alfacalcidol are prolonged than vitamin D because a negative feedback mechanism regulates the final activation step of vitamin D in the kidneys.  Alfacalcidol is available in oral and intravenous formulations. In Canada, it is marketed as ONE-ALPHA, which manages hypocalcemia, secondary hyperparathyroidism, and osteodystrophy in adults with chronic renal failure. In approving European countries, alfacalcidol is also indicated for managing nutritional and malabsorptive rickets and osteomalacia, vitamin D-dependent rickets and osteomalacia, and hypophosphataemic vitamin D resistant rickets and osteomalacia."}]