What is Vitamin D?
Vitamin D is a fat-soluble steroid hormone that supports intestinal absorption of calcium, iron, magnesium, phosphate, and zinc. The two main forms of vitamin Dt are D3 (also known as cholecalciferol) and D2 (ergocalciferol).
D3 is the is the naturally occurring form of vitamin D that is produced by the human body when skin makes contact with direct sunlight. Vitamin D3 can also be derived from animal sources and D2 is the form of vitamin D found in plants.
D3 has been found to be twice as effective as D2 at raising the levels of vitamin D in the human body.