Parathormone influences calcium absorbton in the small intestine by regulating the metabolism of

Options

A. Vitamin - C
B. Vitamin - D
C. Vitamin - `B_(6)`
D. Enterogastrone

Answer

To solve the question regarding how parathormone influences calcium absorption in the small intestine, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Parathormone**:
- Parathormone, also known as parathyroid hormone (PTH), is secreted by the parathyroid glands. Its primary role is to regulate calcium levels in the blood.

2. **Role of Calcium in the Body**:
- Calcium is essential for various bodily functions, including muscle contraction, nerve transmission, and blood clotting. Maintaining adequate levels of calcium in the blood is crucial.

3. **Mechanism of Action**:
- Parathormone increases blood calcium levels through several mechanisms:
- It promotes the reabsorption of calcium from the bones.
- It enhances the reabsorption of calcium in the kidneys.
- It influences the absorption of calcium in the intestines.

4. **Vitamin D's Role**:
- Vitamin D plays a significant role in calcium metabolism. It helps in the absorption of calcium from the small intestine by promoting the synthesis of calcium-binding proteins.
- Parathormone works in conjunction with vitamin D to increase calcium levels in the blood.

5. **Conclusion**:
- Since parathormone influences calcium absorption in the small intestine by regulating the metabolism of vitamin D, the correct answer to the question is **Option B: Vitamin D**.