For people genetically predisposed to lupus, a deficiency of vitamin D may be a catalyst for developing the disease, say scientists at the Oklahoma Medical Research Foundation.

The research by Dr. Judith James and graduate student Lauren Cole could be useful in treating lupus, which has no cure and strikes up to 2 million Americans.

"Vitamin D could be beneficial to lupus patients and people who are at increased risk of developing the disease, such as their family members," James said. "With vitamin D supplements, doctors might be able to reduce the chances of an autoimmune attack," which occurs when the body mistakes its own tissue for foreign invaders.

James and Cole presented their findings at the annual Federation of Clinical Immunology Societies Conference in Boston.

Cole said their research found that in both lupus patients and healthy individuals, low levels of vitamin D correlated with increased autoantibodies -- proteins that attack the body's own tissue.

"By boosting vitamin D levels, we'd hope to see a drop in autoantibodies," Cole said.

Lupus is a chronic autoimmune disease in which the body's immune system turns its defenses against itself. It can affect any part of the body, but it most commonly attacks the skin, joints, blood and kidneys of sufferers.

Sunlight serves as the primary source of vitamin D, which is formed when the skin is exposed to ultraviolet B radiation. But because skin sensitivity to light is a symptom of lupus, James said, patients would likely need supplements to keep their vitamin D levels up. To see more of The Oklahoman, or to subscribe to the newspaper, go to http://www.newsok.com. Copyright (c) 2009, The Oklahoman, Oklahoma City Distributed by McClatchy-Tribune Information Services. For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.