It is especially important for proper night vision. Vitamin A plays an important role in the immune system by helping protect from infections. Beta-carotene is an antioxidant. It has been studied for its role in cancer and heart disease protection. Antioxidants help fight free radicals.
Free radicals are oxygen by-products produced when body cells burn oxygen.
An accumulation of free radicals can damage body cells and tissues. Women, from age 11 on, should get 800 RE per day. There is no increase of vitamin A requirements during pregnancy but lactating women need about 500 RE or more per day. Vitamin A can be stored in the fatty tissues of the body. This can pose a problem for people taking high doses of vitamin A in the form of supplements.