Lactose malabsorption or intolerance occurs in twice as many individuals with Crohn's disease as with ulcerative colitis. Fat malabsorption occurs in one-third of patients with Crohn's disease and occurs most commonly in those who have had terminal ileal resections. Use of prednisone results in increased calcium loss and inhibition of calcium absorption. While Vitamin B 12 deficiency is one of the most widely recognized and treated nutrient deficiencies in IBD, many other nutrient deficiencies may occur. Metabolic bone disease is common in Crohn's disease of the small intestine because of impaired calcium and Vitamin D absorption.
Iron deficiency is common in ulcerative colitis and Crohn's colitis.
The iron deficiency in colonic disease results from small amounts of blood loss. Iron is the main component in blood. Trace nutrients are substances which are absorbed and present in the body in very small amounts. They contribute to important biologic functions. Trace element deficiency occurs in patients with advanced Crohn's disease and is seen primarily in those with compromised oral nutritional intake, advanced small intestine disease and in those who have had significant small intestinal resections.