Nature’s Field Vitamin A keeps your skin, bones, teeth, and eyes protected. Vitamin A is essential for the health of the body?s tissues. Eating food with adequate amounts of vitamin A prevents the development of night blindness and slows down age-related decline of your eyesight. Vitamin A also protects vision, especially at night, helping the eyes adjust to changes in light. Sufficient vitamin A in your diet helps keep your immune system healthy and function at its best.