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Vitamin K Deficiency

Vitamin K Deficiency Overview

Vitamin K is needed for the synthesis of prothrombin, which is a coagulation factor needed for the normal clotting of blood. In the early 1930s, Henrik Dam observed that chicks consuming very low lipid diets developed subdural or muscular hemorrhages and that blood taken from these animals clotted slowly. This hemorrhagic disease could not be cured by supplementation with any other known dietary factor, and Dam proposed the existence of a new fat-soluble factor, vitamin K.

Chickens with a diet deficient in vitamin K have delayed blood clotting and can lose a large amount of blood from even minor injuries. Sulfaquinoxaline can also cause a vitamin K deficiency in chickens, or increase the severity.

Clinical signs of vitamin K deficiency usually occur from 2-3 weeks of being on a vitamin K-deficient diet. Chickens will develop large hemorrhages on their body. Eggs from vitamin-K deficient breeders will cause increased embryo mortality late in incubation.

Clinical Signs

Hemorrhages in body cavity
Thin blood
Poor clotting


  • History
  • Clinical signs
  • Laboratory tests


Vitamin K : Provide oral supplement containing vitamin K or vitamin-K rich food sources (usually green leafy vegetables, such as kale, parsley, sage, basil, thyme) : SelfNutrition data


Scientific References