Which statement is correct about vitamin-D ?

Options

A. ncrease `Ca^(+2)` absorption in GUT
B. Hyposecretion in children produce rickets
C. Increases osteoblastic activity
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding Vitamin D**: Vitamin D is a fat-soluble vitamin that plays a crucial role in calcium and phosphate metabolism in the body.

2. **Evaluating the First Statement**:
- The first statement claims that vitamin D increases calcium absorption in the gut.
- This is correct because vitamin D enhances the intestinal absorption of calcium, which is essential for maintaining bone health.

3. **Evaluating the Second Statement**:
- The second statement mentions that hypo secretion of vitamin D in children produces rickets.
- This is also correct. Rickets is a disease characterized by weak or soft bones in children, often due to a deficiency of vitamin D, calcium, or phosphate.

4. **Evaluating the Third Statement**:
- The third statement states that vitamin D increases osteoplastic activity.
- This statement is correct as well. Vitamin D promotes the activity of osteoblasts (cells responsible for bone formation) and helps in the mineralization of the bone.

5. **Evaluating the Fourth Statement**:
- The last statement is "all of the above."
- Since all the previous statements are correct regarding vitamin D, this statement is also correct.

6. **Conclusion**:
- Since all statements about vitamin D are correct, the correct answer to the question is option 4: "all of the above."

### Final Answer:
The correct statement about vitamin D is: **All of the above (option 4)**.

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