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, which means it protects cells from the daily toxic damage of oxidation.
Review Date 2/2/2019
Updated by: Emily Wax, RD, CNSC, University of Virginia Health System, Charlottesville, VA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.