Vitamin K dependent coagulation factors include:
**Core Concept**
The underlying principle being tested is the role of **Vitamin K** in the synthesis of coagulation factors. Vitamin K is essential for the gamma-carboxylation of glutamic acid residues on certain proteins, making them functional. This process is crucial for the production of coagulation factors.
**Why the Correct Answer is Right**
Vitamin K dependent coagulation factors include **Factors II, VII, IX, and X**, as well as **Proteins C and S**. These factors are synthesized in the liver and require Vitamin K for their activation. The gamma-carboxylation process enables these proteins to bind calcium ions, which is necessary for their interaction with phospholipid surfaces during the coagulation cascade.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not a complete list of Vitamin K dependent factors.
**Option B:** Incorrect as it does not include all the Vitamin K dependent factors.
**Option C:** Incorrect because it is not the correct list of Vitamin K dependent coagulation factors.
**Option D:** Incorrect as the correct answer is not provided in this option.
**Clinical Pearl / High-Yield Fact**
Remember that Vitamin K is essential for the synthesis of coagulation factors, and its deficiency can lead to bleeding disorders. Newborns are at risk of Vitamin K deficiency bleeding due to low Vitamin K levels.
**Correct Answer:** D. Factors II, VII, IX, X, Protein C, and Protein S.