Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucous membranes, and skin. While vitamin A is best known for its vital role in vision, this vitamin also participates in physiological activities related to the immune system, maintenance of epithelial and mucosal tissues, growth, reproduction, and bone development. In food, vitamin A typically occurs as a fat compound called retinyl palmitate. The body converts retinyl palmitate to three metabolically active forms of the vitamin: retinol, retinal, and retinoic acid.