Vitamin K test

 Q: What is 'Vitamin K test' in the evaluation of jaundice?

Answer: First described 80 years ago, vitamin K can be used to differentiate between obstructive jaundice and jaundice due to hepatocellular injury. 

If an elevated INR can be corrected with exogenous vitamin K, it signifies impaired intestinal absorption of fat-soluble vitamins. It is compatible with obstructive jaundice. In contrast, if INR continue to stay elevated despite vitamin K administration, it predicts hepatocellular pathology. Impaired hepatic function keeps INR elevated despite vitamin K on board. Heparocellular damage is mostly accompanied by hypoalbuminemia.

#hepatology

References:

1. Stewart JD. PROTHROMBIN DEFICIENCY AND THE EFFECTS OF VITAMIN K IN OBSTRUCTIVE JAUNDICE AND BILIARY FISTULA. Ann Surg. 1939 Apr;109(4):588-95. doi: 10.1097/00000658-193904000-00008. PMID: 17857347; PMCID: PMC1391301.

2. Johnson MA. Influence of vitamin K on anticoagulant therapy depends on vitamin K status and the source and chemical forms of vitamin K. Nutr Rev. 2005 Mar;63(3):91-7. doi: 10.1111/j.1753-4887.2005.tb00126.x. PMID: 15825811.