Ergocalciferol is a form of Vitamin D, specifically Vitamin D2, that is a prescription medication used to treat hypoparathyroidism (underactive parathyroid), rickets (softening and weakening of the bones) not responding to other medications, and familial hypophosphatemia (low levels of phosphate). Ergocalciferol belongs to a group of drugs called vitamin D analogs, which work by providing the body necessary levels of vitamin D for those who are deficient in this particular vitamin.

This medication comes in capsule form and liquid forms, and is typically taken once a day, with or without food.

There are no common side effects in taking ergocalciferol reported. Rather, serious side effects may occur if too much of the medication is taken.