Vitamin D has two forms: vitamin D2 (ergocalciferol) derived from plant-based sources and vitamin D3 (cholecalciferol ... and Metabolism concluded that a 50,000-IU dose of vitamin D2 should ...
Vitamin D3, a form of vitamin D, promotes strong bones, good immune health, and mental well-being. You can get vitamin D3 from fortified foods, eggs, and fatty fish — or by spending time in the sun.