Why are vitamin `A` and vitamin `C` essential for us? Give their important sources.

Explanation

### Step-by-Step Solution

1. **Understanding the Importance of Vitamins**:
- Vitamins are organic compounds that are crucial for various bodily functions. They play vital roles in maintaining health and preventing diseases.

2. **Vitamin A**:
- **Function**: Vitamin A is essential for maintaining good vision, especially in low light (night vision). It also supports immune function and skin health.
- **Deficiency Effects**: A deficiency in vitamin A can lead to night blindness, which is the inability to see well in dim light. Severe deficiency can also lead to more serious eye problems and overall health issues.
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