Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 8/1/2011
Publication Date: 3/22/2013
Citation: Fu, X., Booth, S. 2013. Vitamin K. In: Allen, L.H., Prentice, A., Caballero, B. editors. Encyclopedia of Human Nutrition. Volume 4. Elsevier. p.398-403. Interpretive Summary:
Technical Abstract: Vitamin K, a fat-soluble vitamin, is an enzyme cofactor for post-translation modification of specific glutamate residues that are converted into '-carboxyglutamic acid (Gla) residues by a vitamin K-dependent (VKD) carboxylase. Seven VKD coagulation proteins are synthesized in the liver. The extra-hepatic VKD proteins include osteocalcin, matrix Gla-protein, Gla-rich protein, periosin, Tgfbi and gas6, and have multiple roles beyond coagulation. Bleeding associated with vitamin K deficiency has been documented among newborns. Undercarboxylation of extra-hepatic proteins has been linked to a variety of age-associated conditions, including abnormal soft tissue calcification.