Antioxidant Supplements

Some antioxidants, such as vitamins C and E and beta-carotene, are also available as dietary supplements.

What are antioxidants?

During their normal activities, our body cells produce highly reactive substances that contain oxygen. Overproduction of these substances can lead to a condition called "oxidative stress," which can damage cells and contribute to chronic diseases such as heart disease and cancer. Our bodies have prevention and repair mechanisms that regulate oxidative stress pathways. Research has shown that antioxidant enzymes are the most important components of this defense system. Phytochemicals that act as antioxidants may also play a role in helping to regulate oxidative stress pathways. These small molecules are the focus of this fact sheet.

As research has progressed, it has become apparent that antioxidants, especially in larger than usual amounts, may not always be beneficial. Large amounts of antioxidants can interfere with important functions of the cell, including its defense mechanisms and normal signaling. In addition, different types of antioxidants may not be interchangeable. Each of the many antioxidants in the body has different properties.

Where do we get the antioxidants we need?

Our bodies produce some of the antioxidants we need. Additional antioxidants come from foods such as fruits, vegetables and grains.