WEDNESDAY, Dec. 10 (HealthDay News) -- An estimated 38 percent of U.S. adults and 12 percent of children use some type of complementary and alternative medicine, a new U.S. government survey finds.

Complementary and alternative medicine -- sometimes called CAM -- is an umbrella term for a collection of wide-ranging medical and health care systems, practices and products that aren't generally considered conventional medicine. It includes herbal supplements, meditation, chiropractic treatment and acupuncture.

The question about CAM use is really the same as that for conventional medicine -- is it safe and effective? For CAM, the answer has been mixed. Some remedies have been found to be safe and effective, some are safe and not effective, and others are unsafe.

"If you are going to use CAM, you should always let your conventional [health care] provider know about it," said survey co-author Richard L. Nahin, acting director of the U.S. National Center for Complementary and Alternative Medicine's division of extramural research.

For the survey, more than 23,300 adults were interviewed about their use of CAM, and, for the first time, more than 9,400 were asked about their children's use of CAM.

The survey found that use of CAM among adults remained about the same from 2002 to 2007, with 36 percent using alternative therapies in 2002 and 38 percent in 2007.

However, use of techniques such as deep breathing, meditation, massage therapy, and yoga increased significantly.

The most common supplements used by adults are fish oil/omega 3/DHA, glucosamine, echinacea, flaxseed oil or pills, and ginseng. The most popular alternative techniques are deep breathing exercises, meditation, chiropractic or osteopathic manipulation, massage and yoga, the survey found.

Adults use CAM most often to treat pain, including back pain, neck pain or problems, joint pain, arthritis, and other musculoskeletal conditions.