Exposure to brodifacoum, the chemical believed to be tied to the recent outbreak, causes the body to block its natural use of Vitamin K, which helps in the process of blood clotting, Lank said. A person who has been exposed to this type of poison would have to take Vitamin K for weeks to months to help manage their symptoms. How quickly someone’s body could eliminate brodifacoum varies on a case-by-case basis because it is dependent on the quantity consumed and how the poison was ingested.