Now that you understand the role of vitamin K in blood clotting, can you explain why Muayyad had to limit his intake of vitamin K–rich foods?

Answer 1

Muayyad’s rare inherited disorder, Factor V Leiden thrombophilia, has caused him to be quite aware of foods high in vitamin K that might exacerbate his blood clotting and interfere with the effectiveness of his “blood thinning” medication. Muayyad’s blood-thinning medication is probably warfarin (Coumadin), whose mechanism is to interfere with vitamin K’s activity and thus the reactions dependent on the vitamin, including reactions necessary for activation of blood clotting factors. If Muayyad consumed too much vitamin K, there would still be enough vitamin K activity to allow dangerous clots to form in his blood despite the medication’s action in reducing its activity. In addition, cranberry juice and alcohol may increase the effect of the medication warfarin, an example of a food-medication interaction that should be checked for all “blood thinning” medications.