Excessive use of antibiotics leads to deficiency disorders.

Explanation

### Step-by-Step Solution

1. **Understanding Antibiotics**:
- Antibiotics are medications that either kill bacteria or inhibit their growth. They are essential in treating bacterial infections.

2. **Excessive Use of Antibiotics**:
- When antibiotics are used excessively, they can lead to antibiotic resistance. This means that bacteria adapt and become resistant to the effects of the antibiotics, making them ineffective.

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