Ergocalciferol, also known as vitamin D2, is a form of vitamin D that is primarily derived from yeast and fungi. It plays a crucial role in maintaining healthy bones by helping the body absorb calcium and phosphorus. Ergocalciferol is often used to treat or prevent vitamin D deficiency, especially in individuals who have limited sun exposure. This vitamin can be obtained through dietary sources, such as fortified foods and supplements. Unlike cholecalciferol (vitamin D3), which is produced in the skin when exposed to sunlight, ergocalciferol is typically obtained from non-animal sources, making it suitable for vegetarians and vegans.