Which vitamin deficiency is found in gastric cancer patients?
**Core Concept**
Vitamin B12 deficiency is common in patients with gastric cancer due to impaired absorption of the vitamin from the stomach. This is often caused by the presence of gastric atrophy and intestinal metaplasia, which can lead to a reduction in the production of intrinsic factor, a protein necessary for vitamin B12 absorption.
**Why the Correct Answer is Right**
The correct answer is related to the impaired absorption of vitamin B12 in gastric cancer patients. Vitamin B12 is absorbed in the terminal ileum, but the presence of intrinsic factor, produced by the parietal cells in the stomach, is necessary for this process. In gastric cancer, the parietal cells can be damaged, leading to a decrease in intrinsic factor production, which in turn results in vitamin B12 deficiency.
**Why Each Wrong Option is Incorrect**
**Option A:** Folate deficiency can occur in various conditions, including pregnancy and alcoholism, but it is not specifically associated with gastric cancer.
**Option B:** Vitamin C deficiency can lead to scurvy, which is characterized by symptoms such as fatigue, malaise, and poor wound healing, but it is not specifically related to gastric cancer.
**Option C:** Vitamin D deficiency can occur in conditions such as osteomalacia or rickets, but it is not specifically associated with gastric cancer.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that vitamin B12 deficiency can also be caused by other conditions, such as pernicious anemia, where the body's immune system attacks the parietal cells, and autoimmune gastritis, where the body's immune system attacks the stomach lining.
**Correct Answer: C. Vitamin B12.**