JoinLiv D3-2000 is a natural, high-biological utilized vitamin D3 (cholecalciferol), which is manufactured by our bodies in response to UVB exposure (sunlight).*Vitamin D3 may improve calcium absorption and provide immune support. Vitamin D3 also promotes bone, teeth, muscle, and heart health.* Vitamin D3 (cholecalciferol) ismore potent than vitamin D2(ergocalciferol).*