Narrator: This is Science Today. Exposure to sunlight has been found to lower blood pressure and cut the risk of heart attack and stroke. Previously, a University of California, San Diego study linked the vitamin D produced by sunlight to a significant reduction in colon and breast cancers. Cedric Garland, who led that study, says many of us do not get enough vitamin D because we block its production using sunscreen to reduce exposure to UV rays.
Garland: Sunscreens completely eliminate the synthesis of vitamin D more effectively than they reduce the risk of cancer or any other outcome. The wisest thing to do would be when a person is out in the sun, to skip the sunscreen for the first 10 or 15 minutes — just keep it in the pocket, allow the sun to create vitamin D in the skin, then put on a hat and if desired, wear a sunscreen — although choose it very carefully to make sure it's a safe sunscreen.
Narrator: Garland explains that one does not need to exceed 15 minutes in the sun because our skin synthesizes all that it needs in that amount of time. For Science Today, I'm Larissa Branin.