🩺 Nursing Question of the Day

Challenge yourself with one exam-style nursing question every day.

✅ Think carefully • ✅ Choose your answer • ✅ Then scroll down to check the explanation.

🩸 Pernicious Anemia & Vitamin B12 Absorption

✅ Answer: (A) Intrinsic factor

📖 What Happens in Pernicious Anemia?

Pernicious anemia is a type of vitamin B12 deficiency caused by impaired production of intrinsic factor, usually due to autoimmune destruction of gastric parietal cells.

Intrinsic factor is essential for the absorption of vitamin B12 in the terminal ileum.

🧪 Why is Intrinsic Factor Important?

Intrinsic factor is a glycoprotein secreted by the parietal cells of the stomach.

Vitamin B12 binds to intrinsic factor and the complex is then absorbed in the terminal ileum.

👉 Without sufficient intrinsic factor, vitamin B12 cannot be absorbed normally, resulting in vitamin B12 deficiency.

⚠️ Important Clinical Features

Vitamin B12 deficiency can produce megaloblastic anemia and, unlike folate deficiency, may also cause neurologic manifestations.

• 🩸 Fatigue and pallor
• 👅 Glossitis
• 🤲 Paresthesia or numbness
• 🚶 Gait disturbance
• 🧠 Cognitive or neurologic changes in severe cases

❌ Why Are the Other Options Wrong?

A. Intrinsic factor
✅ Correct. Pernicious anemia results from deficiency or loss of intrinsic factor, leading to impaired vitamin B12 absorption.

B. Transferrin
❌ Transferrin is a plasma protein that transports iron through the bloodstream. It is not required for intestinal vitamin B12 absorption.

C. Ferritin
❌ Ferritin primarily stores iron inside cells and is commonly used as an indicator of body iron stores.

D. Fibrinogen
❌ Fibrinogen is a plasma protein involved in blood coagulation and is converted to fibrin during clot formation.

📝 Quick Comparison

📌 Exam Tip: If you see pernicious anemia + impaired B12 absorption, immediately think of intrinsic factor deficiency due to gastric parietal cell dysfunction.