Tryptophan takes part in the formation of vitamin nicotinamide.

Explanation

### Step-by-Step Solution:

1. **Identify Tryptophan**: Tryptophan is an amino acid, which is a building block of proteins. It is classified as an essential amino acid because it cannot be synthesized by the body and must be obtained through diet.

2. **Understanding Nicotinamide**: Nicotinamide, also known as niacin or vitamin B3, is a vital nutrient that plays a significant role in various biological processes, including energy metabolism.

3. **Role of Tryptophan in Nicotinamide Formation**: The body can convert tryptophan into nicotinamide. This conversion is part of the metabolic pathways that utilize tryptophan to synthesize this important vitamin.

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