A research team led by a University of Arizona doctor has discovered two proteins connected to irritable bowel disorder and bone-loss, and these proteins may one day be used as supplemental therapy.

About 1.5 million people in the U.S. suffer from Crohn's, ulcerative colitis, and other inflammatory bowel diseases, and about 3,000 of them are children.

Dr. Fayez Ghisham, director of the UA's Steel Children's Research Center, said treatments exist to counter IBD in three ways: healing the intestinal tract, suppressing the immune system, and shutting down inflammatory proteins.

However, researchers and doctors still have a great deal to learn about these diseases, which can cause a variety of symptoms, from abdominal pain and diarrhea, to liver, kidney disease and joint pain.

"Indeed, 20 percent of those patients may present with arthritis,(too)" Ghisham said.

He explained half of IBD patients also have osteopenia - the thinning of the bones - and osteoporosis, putting them at greater risk for fractures.

The team's work may change some of the thinking about treating IBD related bone loss.

"Current dogma in the entire country is to treat this person with vitamin D," he said. However, the team has found that vitamin D "can make you worse if you take it during active inflammation," he added.

These findings suggest that doctors should treat the inflammation first, before starting patients on a vitamin D protocol.