If the entire ileum is resected, what management is required?

• A. Lifelong iron supplementation
• B. Lifelong calcium supplementation
• C. Vitamin B12 supplementation for life
• D. Lifelong vitamin A supplementation

Answer: (C)

The key idea is that the terminal ileum is the crucial site for absorbing the vitamin B12–intrinsic factor complex. If the entire ileum is removed, B12 cannot be absorbed, so deficiency will develop over time. The liver stores B12 for several years, so symptoms may not appear immediately, but once deficiency occurs it leads to megaloblastic anemia and neuropathy. To prevent these problems, lifelong B12 supplementation is required, commonly via injections or high-dose oral B12. The other nutrients listed are not universally required for life after ileal resection: iron is absorbed earlier in the gut, calcium and fat-soluble vitamins like vitamin A can be affected by general fat malabsorption but are not the primary, predictable lifelong need created by removing the ileum.