Question

Gastrectomy patient needs supplemental: (PART A)

• A. Vit c
• B. Vit d
• C. Vit b12
• D. Vit a

Hint:

No stomach = no parietal cells = no intrinsic factor, and intrinsic factor is needed only for vitamin B12.

Answer 1

The Correct Option is C

Step 1: Recall the physiology of vitamin B12 absorption. Dietary vitamin B12 (cobalamin) is absorbed in the terminal ileum, but ONLY when it is bound to intrinsic factor (IF). Intrinsic factor is a glycoprotein secreted by the parietal cells of the gastric body/fundus.

Step 2: Apply it to gastrectomy. Removing the stomach (gastrectomy) removes the parietal cells, so intrinsic factor production stops. Without IF, ingested B12 cannot be absorbed in the ileum, regardless of oral intake. The patient therefore becomes B12 deficient over time (after liver stores, ~2-4 years, are exhausted).

Step 3: Why option C (Vit B12) is correct. Post-gastrectomy patients require life-long parenteral (IM) vitamin B12 supplementation to prevent megaloblastic (pernicious-type) anaemia and subacute combined degeneration of the cord. (Iron deficiency is also common after gastrectomy, but among the listed vitamins B12 is the classic mandatory supplement.)

Step 4: Why the distractors are wrong. (A) Vitamin C is water-soluble and absorbed throughout the small intestine; its absorption does not depend on the stomach. (B) Vitamin D is fat-soluble and absorbed in the small intestine with bile; not specifically lost with gastrectomy. (D) Vitamin A is fat-soluble, absorbed in the small intestine; not dependent on gastric intrinsic factor.

Final Answer: Option C - Vit B12.