Antioxidant vitamins are used in a wide range of conditions where free radical damage is playing a role. Antioxidant vitamin combination is used in the prevention of coronary heart diseases, certain types of cancer, aging as well as free radical damage caused by excessive exercise, illness, certain medications, air pollution, smoke, radiation and pesticides. The main role of the antioxidant vitamins is as follows: _ carotene prevents free radical formation by quenching singlet oxygen, a highly reactive form of oxygen. Vitamin C is another free radical scavenger which deactivates free radicals. It works specially in the plasma, lung fluid, aqueous humour and interstitial fluid. It can increase white blood cell activity; play important roles in the biochemistry of antibodies, prostaglandin E 1 , B and T lymphocytes, and interferon. Vitamin E also scavenges free radicals in the blood along with _ carotene and vitamin C. Moreover, vitamin E is essential to protect against some of the ill effects of smog and smoke. In relation to other nutrients vitamin E protects vitamin A from being destroyed in the body.