Narrator: This is Science Today. New research has shown a clear association between a deficiency in sunlight exposure and breast cancer. Dr. Cedric Garland a professor of family and preventive medicine at the University of California, San Diego's School of Medicine, used a new tool called GLOBOCAN - a database that tracked breast cancer incidence, mortality and prevalence in 175 countries.
Garland: We found that they all conform to the same law - namely, as you get further away from the equator, whether it's New Zealand in the Southern Hemisphere or Iceland in the Northern Hemisphere, you have more and more incidence.
Narrator: Sunlight produces vitamin D in the bloodstream and Garland says it's the vitamin D produced that reduces breast cancer rates.
Garland: Now, people who work in vitamin D and cancer are accepting that vitamin D prevents cancer and are trying to formulate the best way to get this message to physicians, nutritionists and the public. And also to implement the discovery so that it doesn't stay within the walls of the university, but is rather out in the community preventing cancer each day.
Narrator: For Science Today, I'm Larissa Branin.