There are many people in the world who have never heard of vitamin K. Identified in 1929 by Danish scientist Henrik Dam, the nutrient was named vitamin K after its discovery was mentioned in German medical journal which referred to it as Koagulationvitamin.
Vitamin K is perhaps best known for its role in helping blood clot normally. Many people who are deficient in the vitamin notice that they bruise easily, or experience heavy nose bleeding, excessive bleeding from everyday cuts, overly-heavy menstrual bleeding, and even rectal bleeding.