Which of the following vitamins is found in the co-enzymes NAD and NADP?

Options

A. Riboflavin
B. Thiamine
C. Niacin
D. Retinol

Answer

To solve the question "Which of the following vitamins is found in the co-enzymes NAD and NADP?", we can follow these steps:

### Step 1: Understand the question
We need to identify which vitamin is associated with the coenzymes NAD (Nicotinamide adenine dinucleotide) and NADP (Nicotinamide adenine dinucleotide phosphate).

**Hint:** Look for the relationship between vitamins and their corresponding coenzymes.

### Step 2: Identify the options
The options given are:
a. Riboflavin
b. Thiamine
c. Niacin
d. Retinol

**Hint:** Recall the common names and functions of these vitamins.

### Step 3: Analyze each option
- **Riboflavin (Vitamin B2)**: This vitamin is involved in energy production and metabolism but is not related to NAD or NADP.
- **Thiamine (Vitamin B1)**: This vitamin is crucial for carbohydrate metabolism but does not form NAD or NADP.
- **Niacin (Vitamin B3)**: This vitamin is directly related to the formation of NAD and NADP. It is also known for its role in energy metabolism and digestion.
- **Retinol (Vitamin A)**: This vitamin is important for vision and immune function but does not relate to NAD or NADP.

**Hint:** Focus on the vitamin that is known to be a precursor to NAD and NADP.

### Step 4: Conclusion
From the analysis, we can conclude that the vitamin found in the coenzymes NAD and NADP is **Niacin (Vitamin B3)**.

**Final Answer:** c. Niacin