SAN DIEGO -- Vitamin D has been associated with colon health for years, but researchers are just now learning exactly how much you need to reduce the risk of colon cancer.

Researchers at UCSD's Moores Cancer Center say taking 1,000 international units of vitamin D can cut your risk of colon cancer in half.

And getting enough vitamin D isn't difficult.

Your body makes some vitamin D when exposed to the sun. You may also need to take supplements and eat foods fortified with vitamin D. Milk is one of them.

"Recently it's been expanded to be in yogurt, many brands of yogurt, (and) cheese. It's present sometimes in orange juice (and) breakfast cereals, so there is now a wide range of foods that contain it," said Moores Cancer Center researcher Dr. Cedric Garland.

Garland said African Americans should be especially conscious of their vitamin D levels. They are five times more likely than Caucasians to be deficient in vitamin D.