Some studies also suggest that smoking can worsen liver disease caused by excessive intake of alcohol. Depletion of Protective Antioxidants Smoking changes the metabolism of vitamin C in the body. Low levels of these nutrients inhibit the body's ability to neutralize harmful reactive compounds known as free radicals that are found in cigarette smoke. Increased presence of free radicals can put a person at higher risk for chronic diseases such as cardiovascular disease and cancer. Some evidence suggests that smokers may require as much as 200 mg of vitamin C a day to counteract rapid depletion and maintain blood levels similar to nonsmokers.
Tissues containing adequate amounts of vitamin A appear less likely to become cancerous.
Vitamin E may reduce the damage to lung tissue from outside air pollution. Lower zinc levels are found in smokers. Adequate amounts of zinc may reduce the risk of atherosclerosis in people who smoke. Women who smoke during pregnancy have low zinc levels in their blood and are more likely than nonsmokers to have babies deficient in zinc. These babies are at higher risk for birth defects and disease than babies who have received adequate amounts of this mineral.