TUESDAY, Oct. 14 (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.

In the first study of 504 people with inflammatory bowel disease,, researchers at the Medical College of Wisconsin found almost half were vitamin D-deficient at some point, with 11 percent being severely deficient. In patients with Crohn's disease and ulcerative colitis, low levels of vitamin D were linked to increased disease activity. Based on responses to patient questionnaires, those with Crohn's also had a worse quality of life compared to those with the disease who had sufficient levels of vitamin D.

In the other study, researchers from University of Tennessee in Memphis found more than 92 percent of 118 chronic liver patients studied had some level of vitamin D deficiency, with a third being severely deficient. The patients included those with hepatitis C and/or cirrhosis.

"Since deficiency is common among these patients, vitamin D replacement may hopefully prevent osteoporosis and other bone complications related to end-stage liver disease," lead researcher Satheesh P. Nair said in a news release issued by the American College of Gastroenterology.

More information

The National Institutes of Health has more about vitamin D.