Vitamin A, also known as retinol, is essential to the formation of visual purple in the retina, which allows vision in dim light. Beta carotene, the precursor to vitamin A found in vegetables, has antioxidant properties, meaning it protects cells from the toxic damage of oxidation.

Vitamin A helps form and maintain healthy skin, teeth, skeletal and soft tissue, mucous membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye. The main biological function of Vitamin D is promoting normal levels of calcium and phosphorus in the blood.