(HealthDay News) -- People with inflammatory bowel disease or chronic liver disease may be at increased risk of developing vitamin D deficiencies, new research says.

Vitamin D is essential in the body's absorption of calcium, giving the fat-soluble vitamin a critical role in a person having strong, healthy bones.

Two separate studies, presented recently at the American College of Gastroenterology annual meeting, in Orlando, Fla., suggest that patients with certain digestive diseases should have their vitamin D levels regularly monitored.

(HealthDay News) -- Inflammatory bowel disease (IBD) is a chronic illness of the digestive tract. There are two main types: Crohn's disease and ulcerative colitis, the U.S. Department of Health and Human Services says.

The agency offers these suggestions to help keep IBD under control:

* Take certain nutritional supplements. Discuss options with your doctor.
* Reduce the amount of dairy products in your diet.
* Eat a low-fat diet recommended by your doctor.
* Stay away from foods high in undigestible fiber, as well as highly seasoned foods.

WEDNESDAY, May 28 (HealthDay News) -- A molecule produced by intestinal bacteria can eliminate symptoms of inflammatory bowel disease (IBD) in mice, U.S. researchers say.

IBD includes Crohn's disease and ulcerative colitis.