Vitamin D3 (cholecalciferol) or Calciferol
Vitamin D2 (ergocalciferol)
What It Is
Vitamin D is a fat-soluble vitamin that comes in two forms. Vitamin D3 comes from animal sources and is also synthesized in the skin from exposure to sunlight. Vitamin D2 comes from plants such as yeasts and fungi.
Role in the human body
Vitamin D has the important roles of regulating calcium and phosphate levels in the body, bone mineralization, healthy bones and teeth, as well as the normal function of muscles and the immune system. In children it is critical for normal skeletal development. Where it’s found The richest natural sources of vitamin D are fish liver oils and saltwater fish such as sardines, herring, salmon and mackerel. Eggs, meat, milk and butter also contain small amounts.