H was tested for zinc in march 2012 and was low. Dr suggested 15 mg per day for him. The rash on the side if his nose cleared soon after supplementing. Dr tested zinc again this winter and he was normal. Dr said keep him at 15.
Here is a link that I found at the time
http://www.bcm.edu/cnrc/consumer/archives/zinc-Crohn's.htm
Link between low zinc and Crohn's disease symptoms studied
A pilot study designed to determine why children with Crohn's disease have low levels of zinc might lead to more effective treatments for this chronic inflammatory bowel disease.
"Many symptoms seen in Crohn's disease, such as stunted growth, a poor sense of taste and skin rashes, are also characteristic of a zinc deficiency. Because most individuals with Crohn's disease have low serum zinc levels, many question whether a zinc deficiency might be the cause of at least some symptoms," said Dr. Steven Abrams of the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine in Houston and the study's principal investigator.
Crohn's disease is a chronic condition that can affect the entire gastrointestinal tract. Flare-ups are characterized by intestinal inflammation, fever, abdominal pain, severe diarrhea, and bloody stools. Even when the disease is under control, many individuals continue to experience poor appetite and chronic diarrhea, which can affect their nutritional status.
"No one knows whether the low serum zinc levels seen in Crohn's disease is due to diet, poor absorption, or increased losses caused by the disease. But, because zinc is involved in over 70 physiological processes, including cell division and protein formation, it's clear that a zinc deficiency during growth periods can have serious and life-long repercussions," said Dr. Sandra Kim, a Baylor research fellow who is also working on the study.
Abrams and Kim believe that pinpointing where abnormalities in zinc metabolism occur could help determine whether supplementation relieves some Crohn's symptoms. If so, this knowledge might also help researchers identify the best methods for administering supplemental zinc and for monitoring zinc levels.
According to Kim, approximately 10 to 15 percent of the nearly one million individuals with Crohn's disease are diagnosed in childhood. Caucasians suffer most frequently from the disease, but the incidence among Hispanics and blacks living in Westernized cultures is on the rise.
Although the cause is unknown, many believe that the disease is initially triggered by a gastrointestinal infection. One theory suggests that the body somehow fails to properly "turn off" the normal inflammatory immune response once the infection is resolved, which sets up a vicious cycle of intestinal inflammations, diarrhea and other symptoms.
"Understanding how zinc metabolism is affected by Crohn's disease could lead to an improved quality of life for these children," Abrams said.