Loss of parietal cells after a gastrectomy may lead to a deficiency of

• A. Vitamin C
• B. Vitamin E
• C. Vitamin B12
• D. Choline

Answer: (C)

Parietal cells produce intrinsic factor, a protein essential for the absorption of vitamin B12 in the terminal ileum. When parietal cells are lost after a gastrectomy, intrinsic factor production drops, so vitamin B12 cannot be efficiently absorbed. Over time this leads to vitamin B12 deficiency, which causes megaloblastic anemia and can produce neurologic symptoms due to impaired myelin formation.

The other nutrients listed do not depend on intrinsic factor for absorption. Vitamin C absorption occurs in the small intestine through different transport mechanisms; vitamin E is fat-soluble and its uptake relates to fat absorption, not intrinsic factor; choline is absorbed independently of intrinsic factor. Therefore, the deficiency most directly linked to loss of parietal cells is vitamin B12.