Persons with high intakes of dietary vitamin C or citrus fruit have repeatedly been found to have a lower risk of developing cancer. This paper summarizes the epidemiologic literature briefly and provides national data on population intake of this vitamin in the United States. Vitamin C has numerous biologic functions, including collagen, hormone, and neurotransmitter synthesis. With regard to cancer prevention, its role as an antioxidant and free radical scavenger may be of primary importance. Oxidative and free-radical damage to DNA and cell membranes is quite well-established as an important factor in cancer initiation, and substantial evidence indicates that ascorbic acid can help prevent such damage. These laboratory data provide the biologic mechanisms and rationale, whereas epidemiologic data can provide evidence of their relevance to the human population.

High intake of vitamin C or citrus fruit is associated with a lower risk of developing cancer, due to its role as an antioxidant and free radical scavenger.

Vitamin C Status and Cancer