Castle's intrinsic factor is connected with internal absorption of

Options

A. Pyridoxine
B. Riboflavin
C. Thiamine
D. Cobalamine

Answer

**Step-by-Step Solution:**

1. **Understanding Castle's Intrinsic Factor**: Castle's intrinsic factor is a glycoprotein that is secreted by the parietal cells (also known as oxyntic cells) located in the stomach lining. These cells are responsible for producing hydrochloric acid and intrinsic factor.

2. **Function of Castle's Intrinsic Factor**: The primary role of Castle's intrinsic factor is to facilitate the absorption of vitamin B12 (also known as cobalamin) in the intestines. It does this by binding to vitamin B12, forming a complex that is necessary for its absorption.

3. **Absorption Mechanism**: Vitamin B12 is absorbed in the ileum (the last part of the small intestine) through a process that requires the intrinsic factor. Without this factor, vitamin B12 cannot be adequately absorbed, leading to deficiencies.

4. **Identifying the Correct Answer**:
- The question asks what Castle's intrinsic factor is connected with in terms of internal absorption.
- The options provided include:
- Pyridoxine (Vitamin B6)
- Riboflavin (Vitamin B2)
- Thiamine (Vitamin B1)
- Cobalamin (Vitamin B12)
- Since Castle's intrinsic factor is specifically involved in the absorption of vitamin B12, the correct answer is cobalamin.

5. **Conclusion**: Therefore, Castle's intrinsic factor is connected with the internal absorption of cobalamin (vitamin B12).

**Final Answer**: Castle's intrinsic factor is connected with the internal absorption of cobalamin (vitamin B12).

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