WASHINGTON (Reuters) - Federally funded U.S. researchers are starting one of the first trials of a popular ``natural'' supplement for arthritis and joint pain, the National Institutes of Health (NIH) said on Monday.

The $14 million study will check into whether glucosamine and chondroitin work against osteoarthritis. The two supplements are widely sold as an aid to joint pain, both separately and as a package, but few studies have been done on whether they actually work.

``Only a few rather small studies have been published in the worldwide literature, to-date,'' Dr. Stephen Straus, director of the National Center for Complementary and Alternative Medicine (NCCAM), said in a statement.

``Those short-term, controlled clinical trials suggested that glucosamine is effective in relieving pain and increasing range of motion in patients with osteoarthritis,'' Straus added.

``This major new study will provide compelling answers about the safety and effectiveness of glucosamine and/or chondroitin, to the nearly 40 million Americans who suffer with osteoarthritis.''

The NCCAM, one of the National Institutes of Health, will pay for the University of Utah and various other centers around the country study of 1,500 people.

(From Yahoo)