Vitamin D Supplementation as Non-toxic Immunomodulation in Children With Crohn's Disease

Vitamin D is an important nutrient controlling the health and development of our bones. Many patients with inflammatory bowel disease (IBD) are deficient in levels of vitamin D in their bodies. This is probably because vitamin D is lost from inflamed intestinal tissue into the stools. But while much attention has been given to studying the impact of vitamin D deficiency on the bone status of patients with IBD, our understanding of how vitamin D deficiency might affect the immune system in these patients is relatively poor. The investigators intend to study vitamin D supplementation in children with Crohn's disease, ages 8 to 18 years. At the time of enrollment, the investigators will gather data on disease activity using both a simple history and physical exam, as well as blood and stool tests. In addition, the investigators will measure the levels of cathelicidin produced by the immune cells in their blood. The investigators will then supplement 20 children with vitamin D for a total of 6 months. During the study, patients will be seen every two months, where the investigators will monitor their vitamin D levels as well as perform rigorous safety monitoring for toxicity using blood and urine tests. And at study conclusion, the investigators will again judge their disease severity and check their vitamin D levels in addition to tests of cathelicidin levels. The investigators believe that at study conclusion, the investigators will have achieved several important objectives. First, as a public health benefit, the investigators will show that large doses of supplemental vitamin D are safe in children and provide more benefit with less risk. Our patients will achieve those levels of vitamin D agreed by expert opinion that are required to cause effects on the immune system, and the investigators will see an increase in the amount of cathelicidin produced by their immune cells. As an added piece of information, the investigators would like to determine if there are any improvements in disease activity in patients supplemented with vitamin D.