Which of the following patient require Vit B12 supplementation?
**Core Concept**
Vitamin B12 plays a crucial role in the synthesis of myelin, the maintenance of the nervous system, and the formation of red blood cells. A deficiency in vitamin B12 can lead to neurological and hematological disorders. The primary cause of vitamin B12 deficiency is a lack of intrinsic factor, a protein produced in the stomach that facilitates the absorption of vitamin B12.
**Why the Correct Answer is Right**
A patient with pernicious anemia requires vitamin B12 supplementation due to the absence of intrinsic factor. This leads to malabsorption of vitamin B12, resulting in a deficiency. The lack of intrinsic factor is often caused by autoimmune destruction of the gastric parietal cells, which produce intrinsic factor. Without adequate vitamin B12, the body's stores are depleted, leading to anemia, neurological symptoms, and increased homocysteine levels.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while a strict vegetarian diet may lead to a vitamin B12 deficiency, it is not the only cause. Vegetarians who consume animal products or take supplements may not require supplementation.
**Option B:** This option is incorrect because a patient with iron deficiency anemia does not require vitamin B12 supplementation. Iron deficiency anemia is caused by a lack of iron, which can lead to reduced hemoglobin production and anemia.
**Option C:** This option is incorrect because a patient with celiac disease may require vitamin B12 supplementation if they have a deficiency. However, celiac disease itself does not directly cause vitamin B12 deficiency.
**Clinical Pearl / High-Yield Fact**
Patients with pernicious anemia often have a positive titer for intrinsic factor antibodies, which can aid in diagnosis. Vitamin B12 deficiency can also be caused by gastric resection, chronic use of proton pump inhibitors, or a strict vegetarian diet without supplementation.
**Correct Answer:** C.