## **Core Concept**
Avidin is a protein found in raw egg whites that binds to a specific vitamin, rendering it unavailable for absorption in the body. This interaction is significant in nutrition and biochemistry.

## **Why the Correct Answer is Right**
Avidin specifically binds to **Biotin (Vitamin B7)**, which is an essential nutrient involved in various metabolic processes, including energy production and the synthesis of fatty acids and amino acids. The binding of avidin to biotin is very strong and can lead to biotin deficiency if large amounts of raw egg whites are consumed over a period.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Vitamin A is crucial for vision, immune function, and skin health but is not bound by avidin.
- **Option B:** Vitamin C is important for collagen synthesis and as an antioxidant but is not affected by avidin.
- **Option D:** Vitamin D is vital for calcium absorption and bone health but is not bound by avidin.

## **Clinical Pearl / High-Yield Fact**
A key clinical point to remember is that **cooking egg whites denatures avidin**, preventing it from binding to biotin. Therefore, consuming cooked egg whites does not lead to biotin deficiency.

## **Correct Answer:** .