From the Guidelines
Patients with Crohn's disease should have regular monitoring of vitamins B12 and D, as deficiencies in these vitamins are common and can significantly impact morbidity, mortality, and quality of life. According to the most recent and highest quality study 1, vitamin B12 deficiency is prevalent in Crohn's disease, particularly in patients with ileal involvement or resection, and can be effectively managed with intramuscular injections of 1000 mg of vitamin B12 every month. Vitamin D levels should also be checked, as inflammation and malabsorption can lead to deficiency, increasing osteoporosis risk 1. Fat-soluble vitamins A, E, and K, as well as folate, may also require monitoring, especially in patients with significant small bowel involvement or steatorrhea. Iron status should also be assessed, as iron deficiency anemia is prevalent in Crohn's disease due to chronic blood loss and inflammation 1. Regular monitoring every 6-12 months is recommended, with more frequent testing during disease flares or after intestinal resections.
- Key vitamins to monitor in Crohn's disease include:
- Vitamin B12: due to terminal ileum inflammation or resection, which impairs absorption
- Vitamin D: as inflammation and malabsorption can lead to deficiency, increasing osteoporosis risk
- Fat-soluble vitamins A, E, and K: especially in patients with significant small bowel involvement or steatorrhea
- Folate: due to medication interactions or poor dietary intake
- Iron: as iron deficiency anemia is prevalent in Crohn's disease due to chronic blood loss and inflammation
- Supplementation should be tailored to individual deficiencies, with consideration for injectable forms of B12 if ileal absorption is compromised.
From the Research
Vitamins to Check in Crohn's Disease
The following vitamins should be checked in patients with Crohn's disease:
- Vitamin B12: Crohn's disease can involve the small intestine, where vitamin B12 is absorbed, leading to deficiency 2, 3, 4
- Folate: Deficiency is common in Crohn's disease patients, especially those with active disease or ileal resection 2, 4
- Vitamin D: Deficiency is common among Crohn's disease patients, and optimal levels may be required for non-skeletal effects 5
- Iron: Iron deficiency is a common cause of anemia in Crohn's disease patients, and novel iron indices may be required for accurate assessment 6
Risk Factors for Vitamin Deficiencies
Certain factors increase the risk of vitamin deficiencies in Crohn's disease patients:
- Ileal resection: Increases the risk of vitamin B12 deficiency 2, 3
- Disease activity: Increases the risk of folate deficiency 2
- Disease location: Terminal/distal ileal involvement increases the risk of vitamin B12 deficiency 4
- Disease duration: May contribute to vitamin deficiencies, but more research is needed to determine the exact relationship 4