Video Transcript
A patient is instructed to eat more leafy green vegetables by a dietitian as his
tests show that he is likely to have hemophilia, which is a disorder in which blood
does not clot properly. Which of the following vitamins does he need to get from leafy green vegetables for
his case? (A) Vitamin A, (B) vitamin K, (C) vitamin E, or (D) none of the answers are
correct.
You may already be familiar with the fact that there are several different proteins,
enzymes, and factors involved in the cascade of biochemical reactions that cause
blood clotting. If any one of these factors is defective or deficient, this can cause a clotting
disorder, in which the body may be unable to form clots at the site of an
injury.
Several of the proteins involved in the clotting process are produced in the
liver. One of these proteins that plays a very important role in blood clotting is called
prothrombin, which gets converted into an enzyme called thrombin. Thrombin in turn converts the soluble protein fibrinogen into the insoluble protein
fibrin. The fibrin precipitates out of the blood as a network of microscopic fibers. The strands of fibrin formed in this way will reinforce the platelet plug by forming
a net or mesh, which traps red blood cells and more activated platelets. The process in the liver that produces prothrombin requires vitamin K, which means
that a deficiency in vitamin K can cause a clotting disorder.
So the vitamin the patient needs to get from leafy green vegetables is given in
answer choice (B), vitamin K.
