Vitamin D (ergocalciferol-D2, cholecalciferol-D3, alfacalcidol) is a fat-soluble vitamin that helps your body absorb calcium and phosphorus. ... Vitamin D is used to treat and prevent bone disorders (such as rickets, osteomalacia).

Ergocalciferol is used to treat hypoparathyroidism (decreased functioning of the parathyroid glands). Ergocalciferol is also used to treat rickets (softening of the bones caused by vitamin D deficiency) or low levels of phosphate in the blood (hypophosphatemia).

Ergocalciferol is used to treat hypoparathyroidism (decreased functioning of the parathyroid glands). Ergocalciferol is also used to treat rickets (softening of the bones caused by vitamin D deficiency) or low levels of phosphate in the blood (hypophosphatemia)