how are they medically used?
Vitamin K is also part of the suggested treatment regime for poisoning by rodenticide
Vitamin K
Vitamin K is also part of the suggested treatment regime for poisoning by rodenticide (coumarin poisoning). 
what organ contains bacteria that help produce vitamin k The large intestine what vitamin is this? Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. can you name some foods where it is found? Green leafy vegetables
wiki:19578683
Vitamin K [SEP] Medical uses
Vitamin K is also part of the suggested treatment regime for poisoning by rodenticide (coumarin poisoning). Vitamin K treatment may only be necessary in people who deliberately have consumed large amounts of rodenticide or have consumed an unknown amount of rodenticide. Patients are given oral vitamin K to prevent the negative effects of rodenticide poisoning, and this dosing must sometimes be continued for up to nine months in cases of poisoning by "superwarfarin" rodenticides such as brodifacoum. Oral Vitamin K is preferred over other vitamin K routes of administration because it has fewer side effects.