Gastrectomy produces deficiency of which vitamin –
**Core Concept**
Gastrectomy, the surgical removal of part or all of the stomach, can lead to malabsorption of specific nutrients due to the altered anatomy and function of the gastrointestinal tract. The stomach plays a crucial role in the secretion of gastric acid and intrinsic factor, a protein essential for vitamin B12 absorption.
**Why the Correct Answer is Right**
Vitamin B12 is a complex vitamin that requires intrinsic factor, a glycoprotein produced by the parietal cells in the stomach, for its absorption in the terminal ileum. Gastrectomy can lead to a deficiency in intrinsic factor, resulting in impaired vitamin B12 absorption. This deficiency can manifest as megaloblastic anemia, neuropathy, and other neurological symptoms. The lack of intrinsic factor is a critical factor in the development of vitamin B12 deficiency, which is a well-documented consequence of gastrectomy.
**Why Each Wrong Option is Incorrect**
**Option A:** Vitamin B6 is not directly related to gastrectomy or the secretion of intrinsic factor. While vitamin B6 deficiency can cause a range of symptoms, including neurological and dermatological issues, it is not specifically linked to gastrectomy.
**Option C:** Vitamin B2, or riboflavin, is an essential nutrient involved in energy production and can be found in a variety of foods. Gastrectomy does not directly affect vitamin B2 absorption, and deficiency is more commonly associated with dietary restrictions or conditions like celiac disease.
**Option D:** Vitamin B1, or thiamine, is crucial for energy production and can be affected by conditions like celiac disease or Crohn's disease. However, gastrectomy is not a primary risk factor for vitamin B1 deficiency.
**Clinical Pearl / High-Yield Fact**
Gastrectomy patients are at increased risk of developing vitamin B12 deficiency due to the loss of intrinsic factor. This highlights the importance of vitamin B12 supplementation in patients undergoing gastrectomy or those with conditions that impair intrinsic factor production.
**✓ Correct Answer: B. Vitamin B12**