Vitamin D3 is a natural, bio-identical vitamin D supplement. Vitamin D, considered both a hormone and a vitamin, is manufactured in response to skin's exposure to sunlight and is essential to the body's absorption of calcium, cardiovascular, and immune health.
Natural vitamin D3 (cholecalciferol) is four times more potent than synthetic vitamin D2. Vitamin D also maintains adequate serum, calcium and phosphate concentrations to enable bone and muscle health.