Name the vitamin which takes part in blood clotting?

Vitamin K 

The correct answer is option 3. Vitamin K.

The vitamin that is essential for blood clotting is Vitamin K. Vitamin K plays a crucial role in the synthesis of certain proteins required for blood clotting and bone metabolism.

Role of Vitamin K in Blood Clotting

Vitamin K and Coagulation Factors:

Vitamin K is essential for synthesizing several key proteins involved in blood clotting, known as coagulation factors. These include Factors II (Prothrombin), VII, IX, and X. These factors are crucial for the blood clotting cascade, a series of reactions that lead to the formation of a blood clot.

Synthesis of Coagulation Factors:

The liver uses Vitamin K to produce these clotting factors in their active forms. Without sufficient Vitamin K, the liver cannot produce functional clotting factors, which impairs the blood's ability to clot properly.

Mechanism of Action:  

Vitamin K acts as a coenzyme for the enzyme gamma-glutamyl carboxylase, which is responsible for adding carboxyl groups to certain glutamic acid residues on clotting factors. This modification is essential for these factors to bind calcium ions and become active.

Types of Vitamin K:

There are two main forms of Vitamin K:

Vitamin \(K_1\) (Phylloquinone): Found in green leafy vegetables, it is directly involved in the blood clotting process.

Vitamin \(K_2\) (Menaquinone): Found in fermented foods and animal products, it also contributes to bone health and cardiovascular health.

Deficiency and Effects:

A deficiency in Vitamin K can lead to increased bleeding and bruising because the blood clotting process is impaired. This can be particularly dangerous in cases of injury or surgery. To ensure adequate Vitamin K levels, it's important to include green leafy vegetables (like spinach and kale) and certain fermented foods in your diet.

In summary, Vitamin K is vital for the proper functioning of the clotting factors needed to stop bleeding and ensure proper wound healing.