Xerophthalmia in children and nyctalopia (Night blindness ) in adults is caused by the deficiency of vitamin

Options

A. Vitamin A
B. Vitamin B
C. Vitamin C
D. Vitamin D

Answer

**Step-by-Step Solution:**

1. **Understanding the Conditions**:
- Xerophthalmia is a progressive eye disease primarily affecting children, characterized by dryness of the conjunctiva and cornea.
- Nyctalopia, commonly known as night blindness, is the inability to see well in low light or darkness, which can affect adults.

2. **Identifying the Nutritional Deficiency**:
- Both xerophthalmia and nyctalopia are associated with a deficiency in a specific vitamin.
- The question asks which vitamin deficiency leads to these conditions.

3. **Researching Vitamin Functions**:
- Vitamin A is known for its role in maintaining healthy vision, particularly in low-light conditions.
- A deficiency in vitamin A can lead to the drying out of tear ducts and the eyes, contributing to xerophthalmia.
- It also plays a crucial role in the functioning of the retina, which is essential for night vision.

4. **Eliminating Other Options**:
- **Vitamin B**: This is a group of vitamins, and while deficiencies can cause various health issues, they are not directly linked to xerophthalmia or night blindness.
- **Vitamin C**: A deficiency leads to scurvy, which does not relate to the eye conditions mentioned.
- **Vitamin D**: Its deficiency is associated with rickets, affecting bone health, not vision.

5. **Conclusion**:
- Based on the information gathered, the deficiency responsible for both xerophthalmia in children and nyctalopia in adults is confirmed to be **Vitamin A**.

**Final Answer**: The deficiency of Vitamin A causes xerophthalmia in children and nyctalopia (night blindness) in adults.

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