Why is blood clotting abnormal with vitamin k deficiency?

Clotting factors: Vitamin k is used to create several factors in the clotting cascade (the system that ends in a blood clot). If vitamin k isn't there, then those factors are deficient, and blood won't clot as well. This is why newborns get a vit k shot, to avoid something called "hemorrhagic disease of the newborn.".

Bleeding: Vitamin k is a vital component of several clotting proteins, and a deficiency will make your blood thinner. Interestingly, when we place a patient on warfarin, we are creating a kind of vitamin k deficiency, and that is how warfarin works.