Nutritional Deficiencies in Inflammatory Bowel Disease

Most Common Deficiencies

• Iron deficiency anemia occurs in approximately one-third of patients with active IBD and is the most common nutritional deficit 1
• Vitamin D deficiency affects 53-66% of Crohn's disease patients and 44-69% of ulcerative colitis patients 1, 2
• Vitamin B12 deficiency is particularly common and requires monitoring, especially in patients with ileal disease or resection 1, 3

Additional Micronutrient Deficiencies

• Magnesium deficiency occurs in 13-88% of IBD patients, primarily from increased gastrointestinal losses 2, 4
• Up to one-third of IBD patients fail to meet recommended dietary calcium intake 2, 4
• Zinc deficiency occurs in approximately 15% of patients and may predict disease course 5

Mechanisms of Deficiency

• IBD patients develop nutritional deficiencies through multiple pathways: chronic mucosal inflammation causing malabsorption, increased gastrointestinal losses from diarrhea, anatomic changes affecting absorptive capacity, inadequate dietary intake from anorexia, and medication-related nutrient interactions 3, 5, 6
• Corticosteroids increase net protein loss in both children and adults with Crohn's disease 5

Monitoring Considerations

• Many micronutrients are acute phase reactants, making interpretation during active inflammation unreliable 2, 5, 4
• All IBD patients require assessment of nutritional status and screening for weight loss at each clinic appointment and hospital admission 1
• Micronutrient deficiencies should be checked regularly, at least annually, even during remission 5

Clinical Recommendations

• Daily multivitamin supplementation may correct most deficiencies but does not guarantee adequacy; iron, zinc, and vitamin D typically require specific replacement regimens 5
• Oral iron supplementation should not exceed 100 mg elemental iron daily in inactive disease and should be avoided entirely during active inflammation due to impaired absorption 1