The difference between vitamin D
and vitamin D3 is that the latter is a form of vitamin D [1
Vitamin D3 (aka cholecalciferol) is often referred to as the “sunshine vitamin,” as it is produced endogenously in the skin when you are exposed to UVB rays. Vitamin D can also be obtained through diet either as either D2 (present in plants and yeast) or D3 (found in animal sources).
While both vitamin D2 and D3 contribute to overall vitamin D levels in the body, it’s recommended to choose the latter as a supplement. Numerous studies have found D3 is more effective at raising vitamin D levels than D2, as it’s estimated that D3 is up to 87% more potent than D2 [2