Vitamin K (phylloquinone (K1) and menaquinone (K2)) are a group of fat-soluble vitamins essential for normal blood-clotting function. Menaquinone is synthesised by normal flora in the intestine although the amount produced in vivo in the human gut is likely negligible. Vitamin K serves as a coenzyme for the clotting factors II, VII, IX and X. Warfarin inhibits vitamin K by preventing its enzymatic reactivation.
Pathological manifestations are rare. Hypervitaminosis K can lead to jaundice and anaemia in the neonate.
- 1. Pamela C. Champe, Richard A. Harvey (Ph. D.), Denise R. Ferrier. Biochemistry. ISBN: 0781769604
- 2. DiNicolantonio, J., Bhutani, J. and O'Keefe, J. (2015). The health benefits of vitamin K. Open Heart, 2(1), p.e000300. doi: 10.1136/openhrt-2015-000300
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