**Question:** Vit-K deficiency is indicated by:

A. Increased bleeding time
B. Decreased coagulation factors synthesis
C. Improved bleeding time with Vitamin K supplementation
D. Normal bleeding time and coagulation profile

**Core Concept:** Vitamin K is a vitamin essential for the synthesis of coagulation factors II, VII, IX, X, protein C, and protein S. These factors are synthesized in the liver and depend on Vitamin K for their proper synthesis.

**Why the Correct Answer is Right:** Vitamin K deficiency leads to impaired synthesis of coagulation factors II, VII, IX, X, protein C, and protein S. As a result, patients with Vitamin K deficiency exhibit decreased levels of these factors in their blood, which is reflected in prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT).

**Why Each Wrong Option is Incorrect:**

A. Increased bleeding time: Vitamin K deficiency does not directly affect bleeding time, as it does not affect platelet function. Instead, it leads to decreased coagulation factor levels, causing prolonged PT and aPTT.

B. Decreased coagulation factors synthesis: This option is incorrect because Vitamin K deficiency does not directly affect the synthesis of coagulation factors. It is rather the decreased levels of these factors in the blood that leads to the abnormal coagulation profile.

C. Improved bleeding time with Vitamin K supplementation: Vitamin K supplementation improves the synthesis of coagulation factors, which helps restore their blood levels. Consequently, this leads to a normalization of PT and aPTT, not a decrease in bleeding time.

D. Normal bleeding time and coagulation profile: This option is incorrect because Vitamin K deficiency results in decreased levels of coagulation factors. While bleeding time remains normal, the abnormal coagulation profile (increased PT and aPTT) indicates the deficiency of coagulation factors.

**Clinical Pearl:** Vitamin K deficiency should be suspected in patients presenting with prolonged coagulation tests (PT, aPTT) and normal bleeding time. This can help guide therapy, as supplementation of Vitamin K can restore the coagulation profile and prevent unnecessary transfusions or blood component replacement therapy in patients with bleeding diathesis.