Vitamin K may protect against lymphoma

Vitamin K -- found in green leafy vegetables -- may protect against non-Hodgkin lymphoma, U.S. researchers said.

Researchers at the Mayo Clinic in Rochester, Minn., said the risk of developing non-Hodgkin lymphoma -- cancer of the immune system -- was approximately 45 percent lower for those whose vitamin K intake was in the top quarter, vs. those whose intake of the vitamin was in the bottom quarter.