vitamin k

Summary

Summary: A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.

Top Publications

  1. Shea M, Dallal G, Dawson Hughes B, Ordovas J, O Donnell C, Gundberg C, et al. Vitamin K, circulating cytokines, and bone mineral density in older men and women. Am J Clin Nutr. 2008;88:356-63 pubmed
    b>Vitamin K modulates cytokines involved in bone turnover, including interleukin-6 (IL-6) and osteoprotegerin in vitro...
  2. Di Minno M, Russolillo A, Di Minno A, Camera M, Parolari A, Tremoli E. Direct anticoagulant drugs to overcome limitations of vitamin K antagonists. A critical appraisal of data in atrial fibrillation patients. Expert Opin Emerg Drugs. 2013;18:9-23 pubmed publisher
    ..However, the inherent limitations of vitamin K antagonists (VKAs) have made the development of new oral anticoagulants necessary...
  3. Theuwissen E, Cranenburg E, Knapen M, Magdeleyns E, Teunissen K, Schurgers L, et al. Low-dose menaquinone-7 supplementation improved extra-hepatic vitamin K status, but had no effect on thrombin generation in healthy subjects. Br J Nutr. 2012;108:1652-7 pubmed publisher
    b>Vitamin K is required for the carboxylation of Gla-proteins in the liver (coagulation factors) and extra-hepatic tissues, such as bone (osteocalcin, OC), and arterial wall (matrix Gla-protein, MGP)...
  4. Dentali F, Riva N, Crowther M, Turpie A, Lip G, Ageno W. Efficacy and safety of the novel oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of the literature. Circulation. 2012;126:2381-91 pubmed publisher
    Novel oral anticoagulants (NOACs) have been proposed as alternatives to vitamin K antagonists for the prevention of stroke and systemic embolism in patients with atrial fibrillation...
  5. Pottegård A, Friis S, Hallas J. Cancer risk in long-term users of vitamin K antagonists: a population-based case-control study. Int J Cancer. 2013;132:2606-12 pubmed publisher
    Some evidence suggests that long-term use of vitamin K antagonists (VKAs) has a cancer chemopreventive effect. Such an effect would have considerable implications in terms of understanding tumor biology...
  6. Ferland G. Vitamin K and the nervous system: an overview of its actions. Adv Nutr. 2012;3:204-12 pubmed publisher
    The role of vitamin K in the nervous system has been somewhat neglected compared with other physiological systems despite the fact that this nutrient was identified some 40 y ago as essential for the synthesis of sphingolipids...
  7. Scaglione F. New oral anticoagulants: comparative pharmacology with vitamin K antagonists. Clin Pharmacokinet. 2013;52:69-82 pubmed publisher
    ..These novel agents provide numerous benefits over older vitamin K antagonists (VKAs) due to major pharmacological differences...
  8. Ageno W, Gallus A, Wittkowsky A, Crowther M, Hylek E, Palareti G. Oral anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141:e44S-e88S pubmed publisher
    ..out a standard review of published articles focusing on the laboratory and clinical characteristics of the vitamin K antagonists; the direct thrombin inhibitor, dabigatran etexilate; and the direct factor Xa inhibitor, ..
  9. Misra D, Booth S, Tolstykh I, Felson D, Nevitt M, Lewis C, et al. Vitamin K deficiency is associated with incident knee osteoarthritis. Am J Med. 2013;126:243-8 pubmed publisher
    ..There are no treatments available to prevent the structural pathology of osteoarthritis. Because of vitamin K's role in regulating skeletal mineralization, it has potential to be a preventative option for osteoarthritis...

More Information

Publications85

  1. Schroecksnadel S, Gostner J, Jenny M, Kurz K, Schennach H, Weiss G, et al. Immunomodulatory effects in vitro of vitamin K antagonist acenocoumarol. Thromb Res. 2013;131:e264-9 pubmed publisher
    ..To examine the potential impact of vitamin K-antagonist acenocoumarol (Sintrom) on the inflammatory response we investigated its effect on freshly isolated ..
  2. Kakkar A, Mueller I, Bassand J, Fitzmaurice D, Goldhaber S, Goto S, et al. Risk profiles and antithrombotic treatment of patients newly diagnosed with atrial fibrillation at risk of stroke: perspectives from the international, observational, prospective GARFIELD registry. PLoS ONE. 2013;8:e63479 pubmed publisher
    ..These contemporary observational worldwide data on non-valvular atrial fibrillation, collected at the end of the vitamin K antagonist-only era, indicate that these drugs are frequently not being used according to stroke risk scores and ..
  3. Mahaffey K, Hellkamp A, Patel M, Hannan K, Schwabe K, Nessel C, et al. End of study transition from study drug to open-label vitamin K antagonist therapy: the ROCKET AF experience. Circ Cardiovasc Qual Outcomes. 2013;6:470-8 pubmed publisher
    ..the 30 days after the end of study (EOS) visit when participants transitioned from blinded therapy to open-label vitamin K antagonist...
  4. Walther B, Karl J, Booth S, Boyaval P. Menaquinones, bacteria, and the food supply: the relevance of dairy and fermented food products to vitamin K requirements. Adv Nutr. 2013;4:463-73 pubmed publisher
    b>Vitamin K exists in the food supply as phylloquinone, a plant-based form and as menaquinones (MKs), a collection of isoprenologues mostly originating from bacterial synthesis...
  5. Pasierski T. Vitamin K antagonists in anticoagulant therapy of patients with cancer. Pol Arch Med Wewn. 2012;122:60-4 pubmed
    ..Prolonged use of low-molecular-weight heparin in cancer patients provides better VTE prophylaxis compared with vitamin K antagonists. Both therapeutic options have a similar safety profile...
  6. Bruins Slot K, Berge E. Factor Xa inhibitors versus vitamin K antagonists for preventing cerebral or systemic embolism in patients with atrial fibrillation. Cochrane Database Syst Rev. 2013;:CD008980 pubmed publisher
    Anticoagulant treatment with vitamin K antagonists (VKAs) is aimed at preventing thromboembolic complications and has been the therapy of choice for most people with non-valvular atrial fibrillation (AF) for many decades...
  7. Sun Y, Song H, Li J, Jiang M, Li Y, Zhou J, et al. Active site binding and catalytic role of bicarbonate in 1,4-dihydroxy-2-naphthoyl coenzyme A synthases from vitamin K biosynthetic pathways. Biochemistry. 2012;51:4580-9 pubmed
    ..The unique location of the bicarbonate ion in relation to the expected position of the substrate ?-proton in the enzyme's active site suggests a critical catalytic role for the anionic cofactor as a catalytic base in enolate formation. ..
  8. Fusaro M, Noale M, Viola V, Galli F, Tripepi G, Vajente N, et al. Vitamin K, vertebral fractures, vascular calcifications, and mortality: VItamin K Italian (VIKI) dialysis study. J Bone Miner Res. 2012;27:2271-8 pubmed publisher
    b>Vitamin K (vitamin K1 or phylloquinone and vitamin K2, a series of menaquinones [MKs]) is involved in the production of bone and matrix amino acid ?-carboxy-glutamic acid (Gla) proteins, regulating bone and vascular calcification...
  9. Lamberts M, Olesen J, Ruwald M, Hansen C, Karasoy D, Kristensen S, et al. Bleeding after initiation of multiple antithrombotic drugs, including triple therapy, in atrial fibrillation patients following myocardial infarction and coronary intervention: a nationwide cohort study. Circulation. 2012;126:1185-93 pubmed publisher
    ..hospitalization) bleeding was determined according to antithrombotic treatment regimen: triple therapy (TT) with vitamin K antagonist (VKA)+aspirin+clopidogrel, VKA+antiplatelet, and dual antiplatelet therapy with aspirin+clopidogrel...
  10. Gundberg C, Lian J, Booth S. Vitamin K-dependent carboxylation of osteocalcin: friend or foe?. Adv Nutr. 2012;3:149-57 pubmed publisher
    ..The presence of 3 vitamin K-dependent ? carboxyglutamic acid residues is critical for osteocalcin's structure, which appears to regulate the ..
  11. Sherwood M, Douketis J, Patel M, Piccini J, Hellkamp A, Lokhnygina Y, et al. Outcomes of temporary interruption of rivaroxaban compared with warfarin in patients with nonvalvular atrial fibrillation: results from the rivaroxaban once daily, oral, direct factor Xa inhibition compared with vitamin K antagonism for prevention of. Circulation. 2014;129:1850-9 pubmed publisher
    ..In the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF), a randomized, double-..
  12. Chatrou M, Winckers K, Hackeng T, Reutelingsperger C, Schurgers L. Vascular calcification: the price to pay for anticoagulation therapy with vitamin K-antagonists. Blood Rev. 2012;26:155-66 pubmed publisher
    b>Vitamin K-antagonists (VKA) are the most widely used anti-thrombotic drugs with substantial efficacy in reducing risk of arterial and venous thrombosis...
  13. Schurgers L, Joosen I, Laufer E, Chatrou M, Herfs M, Winkens M, et al. Vitamin K-antagonists accelerate atherosclerotic calcification and induce a vulnerable plaque phenotype. PLoS ONE. 2012;7:e43229 pubmed publisher
    b>Vitamin K-antagonists (VKA) are treatment of choice and standard care for patients with venous thrombosis and thromboembolic risk. In experimental animal models as well as humans, VKA have been shown to promote medial elastocalcinosis...
  14. Hodroge A, Matagrin B, Moreau C, Fourel I, Hammed A, Benoit E, et al. VKORC1 mutations detected in patients resistant to vitamin K antagonists are not all associated with a resistant VKOR activity. J Thromb Haemost. 2012;10:2535-43 pubmed publisher
    The VKORC1 gene codes for the VKORC1 enzyme, which is responsible for the reduction of vitamin K epoxide into vitamin K. VKORC1 enzyme is the target of vitamin K antagonists (VKA)...
  15. Meehan R, Tavares M, Sweeney J. Clinical experience with oral versus intravenous vitamin K for warfarin reversal. Transfusion. 2013;53:491-8; quiz 490 pubmed publisher
    ..The use of vitamin K is an alternate strategy...
  16. Boxma P, van den Berg E, Geleijnse J, Laverman G, Schurgers L, Vermeer C, et al. Vitamin k intake and plasma desphospho-uncarboxylated matrix Gla-protein levels in kidney transplant recipients. PLoS ONE. 2012;7:e47991 pubmed publisher
    b>Vitamin K is essential for activation of ?-carboxyglutamate (Gla)-proteins including the vascular calcification inhibitor matrix Gla-protein (MGP)...
  17. Gely Pernot A, Coronas V, Harnois T, Prestoz L, Mandairon N, Didier A, et al. An endogenous vitamin K-dependent mechanism regulates cell proliferation in the brain subventricular stem cell niche. Stem Cells. 2012;30:719-31 pubmed publisher
    ..The endogenous mechanisms underpinning SVZ stem and progenitor cell proliferation are not fully elucidated. Vitamin K-dependent proteins (VKDPs) are mainly secreted factors that were initially discovered as major regulators of ..
  18. Ferland G. The discovery of vitamin K and its clinical applications. Ann Nutr Metab. 2012;61:213-8 pubmed publisher
    b>Vitamin K was discovered fortuitously in 1929 as part of experiments on sterol metabolism and was immediately associated with blood coagulation...
  19. Schurgers L, Uitto J, Reutelingsperger C. Vitamin K-dependent carboxylation of matrix Gla-protein: a crucial switch to control ectopic mineralization. Trends Mol Med. 2013;19:217-26 pubmed publisher
    ..The discovery that the vitamin K-dependent matrix Gla-protein (MGP) is a strong inhibitor of vascular calcification has propelled our mechanistic ..
  20. Plichart M, Berrut G, Maubourguet N, Jeandel C, Emeriau J, Ankri J, et al. Use of vitamin K antagonist therapy in geriatrics: a French national survey from the French Society of Geriatrics and Gerontology (SFGG). Drugs Aging. 2013;30:1019-28 pubmed publisher
    We aimed to evaluate the quality and determinants of vitamin K antagonists (VKA) control among very elderly patients in geriatric settings...
  21. Haraikawa M, Tsugawa N, Sogabe N, Tanabe R, Kawamura Y, Okano T, et al. Effects of gamma-glutamyl carboxylase gene polymorphism (R325Q) on the association between dietary vitamin K intake and gamma-carboxylation of osteocalcin in young adults. Asia Pac J Clin Nutr. 2013;22:646-54 pubmed publisher
    ..In the present study, we investigated the effect of GGCX polymorphism (974G>A) on the correlations among the vitamin K in-take, level of serum vitamin K, and ratio of undercarboxylated osteocalcin (ucOC) to intact osteocalcin (OC) ..
  22. Ferland G. Vitamin K, an emerging nutrient in brain function. Biofactors. 2012;38:151-7 pubmed publisher
    Historically discovered for its role in blood coagulation, there is now convincing evidence that vitamin K has important actions in the nervous system...
  23. Holbrook A, Schulman S, Witt D, Vandvik P, Fish J, Kovacs M, et al. Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141:e152S-e184S pubmed publisher
    ..Strong recommendations include targeting an international normalized ratio of 2.0 to 3.0 for patients on vitamin K antagonist therapy (Grade 1B) and not routinely using pharmacogenetic testing for guiding doses of vitamin K ..
  24. Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M, et al. Aspirin for preventing the recurrence of venous thromboembolism. N Engl J Med. 2012;366:1959-67 pubmed publisher
    ..Extending anticoagulation prevents recurrences but is associated with increased bleeding. The benefit of aspirin for the prevention of recurrent venous thromboembolism is unknown...
  25. Theuwissen E, Smit E, Vermeer C. The role of vitamin K in soft-tissue calcification. Adv Nutr. 2012;3:166-73 pubmed publisher
    Seventeen vitamin K-dependent proteins have been identified to date of which several are involved in regulating soft-tissue calcification...
  26. Dalmeijer G, van der Schouw Y, Vermeer C, Magdeleyns E, Schurgers L, Beulens J. Circulating matrix Gla protein is associated with coronary artery calcification and vitamin K status in healthy women. J Nutr Biochem. 2013;24:624-8 pubmed publisher
    Matrix Gla protein (MGP) is a vitamin K-dependent protein and an inhibitor of vascular calcification. Vitamin K is required for the carboxylation of MGP and can thereby reduce calcification...
  27. Siegal D, Yudin J, Kaatz S, Douketis J, Lim W, Spyropoulos A. Periprocedural heparin bridging in patients receiving vitamin K antagonists: systematic review and meta-analysis of bleeding and thromboembolic rates. Circulation. 2012;126:1630-9 pubmed
    ..bridging with unfractionated heparin or low-molecular-weight heparin aims to reduce the risk of thromboembolic events in patients receiving long-term vitamin K antagonists. Optimal periprocedural anticoagulation has not been established.
  28. Henkens I, Hazenoot T, Boonstra A, Huisman M, Vonk Noordegraaf A. Major bleeding with vitamin K antagonist anticoagulants in pulmonary hypertension. Eur Respir J. 2013;41:872-8 pubmed publisher
    b>Vitamin K antagonists are advised in pulmonary arterial hypertension patients despite a lack of safety data. We reviewed major bleeding in three classes of pulmonary hypertension patients, all receiving vitamin K antagonists...
  29. Silva de Assis M, Nascimento Cruz L, Zuchinali P, Rohde L, Rejane Rabelo E. Does treatment guided by vitamin K in the diet alter the quality of life of anticoagulated patients?. Nutr Hosp. 2012;27:1328-33 pubmed publisher
    ..quality of life (HRQoL) is altered in patients undergoing a treatment strategy guided by changes in dietary vitamin K. This study is a randomized clinical trial carried out with chronic oral anticoagulation outpatients randomized ..
  30. Piccini J, Stevens S, Chang Y, Singer D, Lokhnygina Y, Go A, et al. Renal dysfunction as a predictor of stroke and systemic embolism in patients with nonvalvular atrial fibrillation: validation of the R(2)CHADS(2) index in the ROCKET AF (Rivaroxaban Once-daily, oral, direct factor Xa inhibition Compared with vitamin . Circulation. 2013;127:224-32 pubmed publisher
    ..In ROCKET AF (Rivaroxaban Once-daily, oral, direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation), 14 264 patients with nonvalvular ..
  31. Voong K, Harrington D, Goldsmith D. Vitamin K status in chronic kidney disease: a report of a study and a mini-review. Int Urol Nephrol. 2013;45:1339-44 pubmed publisher
    Hepatic vitamin K-dependent proteins (e.g., Factors II, VII, IX and X) form part of the clotting cascade...
  32. Goodman S, Wojdyla D, Piccini J, White H, Paolini J, Nessel C, et al. Factors associated with major bleeding events: insights from the ROCKET AF trial (rivaroxaban once-daily oral direct factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and embolism trial in atrial fibrillation). J Am Coll Cardiol. 2014;63:891-900 pubmed publisher
    This study sought to report additional safety results from the ROCKET AF (Rivaroxaban Once-daily oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation).
  33. Flaker G, Eikelboom J, Shestakovska O, Connolly S, Kaatz S, Budaj A, et al. Bleeding during treatment with aspirin versus apixaban in patients with atrial fibrillation unsuitable for warfarin: the apixaban versus acetylsalicylic acid to prevent stroke in atrial fibrillation patients who have failed or are unsuitable for vita. Stroke. 2012;43:3291-7 pubmed publisher
    ..comparable bleeding risks when compared with aspirin in patients with atrial fibrillation who are unsuitable for vitamin k antagonist therapy...
  34. Vanakker O, Martin L, Schurgers L, Quaglino D, Costrop L, Vermeer C, et al. Low serum vitamin K in PXE results in defective carboxylation of mineralization inhibitors similar to the GGCX mutations in the PXE-like syndrome. Lab Invest. 2010;90:895-905 pubmed publisher
    ..This post-translational modification is catalyzed by the gammaglutamyl carboxylase GGCX and requires vitamin K (VK) as an essential co-factor...
  35. Cairns J, Connolly S, McMurtry S, Stephenson M, Talajic M. Canadian Cardiovascular Society atrial fibrillation guidelines 2010: prevention of stroke and systemic thromboembolism in atrial fibrillation and flutter. Can J Cardiol. 2011;27:74-90 pubmed publisher
    ..Major bleeding with vitamin K antagonists varies from about 1% to over 12% per year and is related to a number of risk factors...
  36. Holden R, Morton A, Garland J, Pavlov A, Day A, Booth S. Vitamins K and D status in stages 3-5 chronic kidney disease. Clin J Am Soc Nephrol. 2010;5:590-7 pubmed publisher
    b>Vitamin K, vitamin K-dependent proteins, and vitamin D may be involved in the regulation of calcification in chronic kidney disease (CKD)...
  37. Pritchard J, Seechurn T, Atkinson S. A food frequency questionnaire for the assessment of calcium, vitamin D and vitamin K: a pilot validation study. Nutrients. 2010;2:805-19 pubmed publisher
    The study objective was to validate a food frequency questionnaire (FFQ) to assess calcium, vitamin D and vitamin K intakes in overweight and obese postmenopausal community-dwelling women...
  38. Ezekowitz M, Wallentin L, Connolly S, Parekh A, Chernick M, Pogue J, et al. Dabigatran and warfarin in vitamin K antagonist-naive and -experienced cohorts with atrial fibrillation. Circulation. 2010;122:2246-53 pubmed publisher
    The comparison of anticoagulants dabigatran and warfarin might be most equitable in vitamin K antagonist (VKA)-naive patients...
  39. Parker A, Waddington S, Nicol C, Shayakhmetov D, Buckley S, Denby L, et al. Multiple vitamin K-dependent coagulation zymogens promote adenovirus-mediated gene delivery to hepatocytes. Blood. 2006;108:2554-61 pubmed
    ..Here, we show that hepatocyte transduction in vitro can be enhanced by the vitamin K-dependent factors FX, protein C, and FVII in addition to FIX but not by prothrombin (FII), FXI, and FXII...
  40. Bhatia M, Talawadekar G, Parihar S, Smith A. An audit of the role of vitamin K in the reversal of International Normalised Ratio (INR) in patients undergoing surgery for hip fracture. Ann R Coll Surg Engl. 2010;92:473-6 pubmed publisher
    ..In the second part of the audit, 45 patients with INR above 1.5 were given a single dose of vitamin K (1 mg i.v.) in addition to stopping warfarin. The mean difference in the time for INR < 1...
  41. Schurgers L, Spronk H, Soute B, Schiffers P, DeMey J, Vermeer C. Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats. Blood. 2007;109:2823-31 pubmed
    ..Matrix Gla protein (MGP) is a potent inhibitor of AC, and its activity depends on vitamin K (VK)...
  42. Shea M, O Donnell C, Hoffmann U, Dallal G, Dawson Hughes B, Ordovas J, et al. Vitamin K supplementation and progression of coronary artery calcium in older men and women. Am J Clin Nutr. 2009;89:1799-807 pubmed publisher
    Coronary artery calcification (CAC) is an independent predictor of cardiovascular disease. A preventive role for vitamin K in CAC progression has been proposed on the basis of the properties of matrix Gla protein (MGP) as a vitamin K-..
  43. Patriquin C, Crowther M. Treatment of warfarin-associated coagulopathy with vitamin K. Expert Rev Hematol. 2011;4:657-65; quiz 666-7 pubmed publisher
    ..As warfarin exerts its effect by impairing formation of the vitamin K-dependent clotting factors, a cornerstone of WAC management is vitamin K replacement...
  44. Jacobs L. Warfarin pharmacology, clinical management, and evaluation of hemorrhagic risk for the elderly. Cardiol Clin. 2008;26:157-67, v pubmed publisher
    Warfarin, a vitamin K antagonist, is currently the most extensively used oral anticoagulant world-wide. It is prescribed for a variety of indications and has undergone extensive clinical study...
  45. Schaefer C, Hannemann D, Meister R, Elefant E, Paulus W, Vial T, et al. Vitamin K antagonists and pregnancy outcome. A multi-centre prospective study. Thromb Haemost. 2006;95:949-57 pubmed
    b>Vitamin K antagonists (VKA) are known to act as teratogens; however, there is still uncertainty about the relative risk for birth defects and the most sensitive period...
  46. Leissinger C, Blatt P, Hoots W, Ewenstein B. Role of prothrombin complex concentrates in reversing warfarin anticoagulation: a review of the literature. Am J Hematol. 2008;83:137-43 pubmed
    ..The goal of urgent warfarin reversal is to elevate or replace vitamin K-dependent clotting factors...
  47. Takahashi D, Shirahata A, Itoh S, Takahashi Y, Nishiguchi T, Matsuda Y. Vitamin K prophylaxis and late vitamin K deficiency bleeding in infants: fifth nationwide survey in Japan. Pediatr Int. 2011;53:897-901 pubmed publisher
    In 1980, the first nationwide survey on late vitamin K deficiency bleeding (VKDB) in infants was conducted in Japan, and it was followed by the second, third and fourth nationwide surveys in 1985, 1988 and 1991, respectively...
  48. Garcia A, Reitsma P. VKORC1 and the vitamin K cycle. Vitam Horm. 2008;78:23-33 pubmed publisher
    b>Vitamin K epoxide, a product of gamma-carboxylation, must be rapidly recycled to its reduced form before it can be reused. The set of sequential reactions that guarantees vitamin K recycling is known as the vitamin K cycle...
  49. Buller H, Deitchman D, Prins M, Segers A. Efficacy and safety of the oral direct factor Xa inhibitor apixaban for symptomatic deep vein thrombosis. The Botticelli DVT dose-ranging study. J Thromb Haemost. 2008;6:1313-8 pubmed publisher
    ..5 mg twice-daily, 10 mg twice-daily, or 20 mg once-daily, or low molecular weight heparin (LMWH) followed by a vitamin K antagonist (VKA)...
  50. Darghouth D, Hallgren K, Shtofman R, Mrad A, Gharbi Y, Maherzi A, et al. Compound heterozygosity of novel missense mutations in the gamma-glutamyl-carboxylase gene causes hereditary combined vitamin K-dependent coagulation factor deficiency. Blood. 2006;108:1925-31 pubmed
    Hereditary combined vitamin K-dependent (VKD) coagulation factor deficiency is an autosomal recessive bleeding disorder associated with defects in either the gamma-carboxylase, which carboxylates VKD proteins to render them active, or ..
  51. Geerts W, Bergqvist D, Pineo G, Heit J, Samama C, Lassen M, et al. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008;133:381S-453S pubmed publisher
    ..hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or a vitamin K antagonist (VKA); international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0 (each Grade 1A)...
  52. Wild D, Murray M, Donatti C. Patient perspectives on taking vitamin K antagonists: a qualitative study in the UK, USA and Spain. Expert Rev Pharmacoecon Outcomes Res. 2009;9:467-74 pubmed publisher
    Limitations of vitamin K antagonists (VKAs) include frequent monitoring, dietary restrictions and drug interactions...
  53. Kearon C, Kahn S, Agnelli G, Goldhaber S, Raskob G, Comerota A. Antithrombotic therapy for venous thromboembolic disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008;133:454S-545S pubmed publisher
    ..with LMWH, UFH or fondaparinux for at least 5 days rather than a shorter period (Grade 1C); and initiation of vitamin K antagonists (VKAs) together with LMWH, UFH, or fondaparinux on the first treatment day, and discontinuation of ..
  54. Schurgers L, Cranenburg E, Vermeer C. Matrix Gla-protein: the calcification inhibitor in need of vitamin K. Thromb Haemost. 2008;100:593-603 pubmed
    Among the proteins involved in vascular calcium metabolism, the vitamin K-dependent matrix Gla-protein (MGP) plays a dominant role...
  55. Li J, Wang H, Rosenberg P. Vitamin K prevents oxidative cell death by inhibiting activation of 12-lipoxygenase in developing oligodendrocytes. J Neurosci Res. 2009;87:1997-2005 pubmed publisher
    ..We previously demonstrated a novel function of phylloquinone (vitamin K(1)) and menaquinone 4 (MK-4; a major form of vitamin K2) in protecting pre-OLs and immature neurons against ..
  56. Kimura R, Kokubo Y, Miyashita K, Otsubo R, Nagatsuka K, Otsuki T, et al. Polymorphisms in vitamin K-dependent gamma-carboxylation-related genes influence interindividual variability in plasma protein C and protein S activities in the general population. Int J Hematol. 2006;84:387-97 pubmed
    gamma-Glutamyl carboxylation, a reaction essential for the activity of vitamin K-dependent proteins, requires the concerted actions of gamma-glutamyl carboxylase (GGCX), vitamin K 2, 3-epoxide reductase complex 1 (VKORC1), and the ..
  57. Nakagawa K, Hirota Y, Sawada N, Yuge N, Watanabe M, Uchino Y, et al. Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme. Nature. 2010;468:117-21 pubmed publisher
    ..Our results show that UBIAD1 is a human MK-4 biosynthetic enzyme; this identification will permit more effective decisions to be made about vitamin?K intake and bone health. ..
  58. Fang Y, Hu C, Tao X, Wan Y, Tao F. Effect of vitamin K on bone mineral density: a meta-analysis of randomized controlled trials. J Bone Miner Metab. 2012;30:60-8 pubmed publisher
    A number of randomized controlled trials (RCTs) examining the role of vitamin K on bone mineral density (BMD) have yielded inconsistent results. We performed a meta-analysis of these trials to assess the effect of vitamin K on BMD...
  59. Rost S, Geisen C, Fregin A, Seifried E, Muller C, Oldenburg J. Founder mutation Arg485Pro led to recurrent compound heterozygous GGCX genotypes in two German patients with VKCFD type 1. Blood Coagul Fibrinolysis. 2006;17:503-7 pubmed
    ..bleeding disorder caused by mutations in either the gamma-glutamyl carboxylase gene (VKCFD type 1) or the vitamin K epoxide reductase gene (VKCFD type 2)...
  60. Dentali F, Ageno W, Crowther M. Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms. J Thromb Haemost. 2006;4:1853-63 pubmed
    ..Low dose oral vitamin K rapidly and reliably returns the international normalized ratio (INR) to the usual therapeutic range in non-..
  61. Kulman J, Harris J, Nakazawa N, Ogasawara M, Satake M, Davie E. Vitamin K-dependent proteins in Ciona intestinalis, a basal chordate lacking a blood coagulation cascade. Proc Natl Acad Sci U S A. 2006;103:15794-9 pubmed publisher
    We have isolated and sequenced several cDNAs derived from the sea squirt Ciona intestinalis that encode vitamin K-dependent proteins...
  62. Keeling D. International Normalized Ratio in patients not on vitamin K antagonists. J Thromb Haemost. 2007;5:188-9 pubmed
  63. Marongiu F, Finazzi G, Pengo V, Poli D, Testa S, Tripodi A. Management of special conditions in patients on vitamin K antagonists. Intern Emerg Med. 2012;7:407-13 pubmed
    Physicians are occasionally faced with difficult situations in the management of vitamin K antagonists (VKA) due to the lack of sound data available in controlled studies on certain conditions...
  64. Oldenburg J, Bevans C, Fregin A, Geisen C, Müller Reible C, Watzka M. Current pharmacogenetic developments in oral anticoagulation therapy: the influence of variant VKORC1 and CYP2C9 alleles. Thromb Haemost. 2007;98:570-8 pubmed
    ..Furthermore, concomitant application of low dose vitamin K may significantly reduce intra-individual coumarin dose variation and, thus, may stabilize oral anticoagulation ..
  65. Buller H, Cohen A, Davidson B, Decousus H, Gallus A, Gent M, et al. Idraparinux versus standard therapy for venous thromboembolic disease. N Engl J Med. 2007;357:1094-104 pubmed
    Venous thromboembolism is treated with unfractionated heparin or low-molecular-weight heparin, followed by a vitamin K antagonist...
  66. Denas G, Marzot F, Offelli P, Stendardo A, Cucchini U, Russo R, et al. Effectiveness and safety of a management protocol to correct over-anticoagulation with oral vitamin K: a retrospective study of 1,043 cases. J Thromb Thrombolysis. 2009;27:340-7 pubmed publisher
    Timely reversal of excessive anticoagulation is important in preventing bleeding complications. The use of vitamin K in correcting over-anticoagulation is widely accepted to be superior to discontinuation of therapy but its effectiveness ..
  67. Schick K, Fertmann J, Jauch K, Hoffmann J. Prothrombin complex concentrate in surgical patients: retrospective evaluation of vitamin K antagonist reversal and treatment of severe bleeding. Crit Care. 2009;13:R191 pubmed publisher
    Prothrombin complex concentrates are recommended for rapid reversal of vitamin K anticoagulants...
  68. Berkner K. Vitamin K-dependent carboxylation. Vitam Horm. 2008;78:131-56 pubmed publisher
    b>Vitamin K-dependent (VKD) protein carboxylation uses vitamin K epoxidation to convert Glus to carboxylated Glus (Glas), rendering VKD proteins active in physiologies that include hemostasis, apoptosis, bone mineralization, calcium ..
  69. Wallin R, Wajih N, Hutson S. VKORC1: a warfarin-sensitive enzyme in vitamin K metabolism and biosynthesis of vitamin K-dependent blood coagulation factors. Vitam Horm. 2008;78:227-46 pubmed publisher
    The recently discovered enzyme VKORC1 of the vitamin K cycle, which is the target for the anticoagulant drug warfarin, has opened new opportunities to understand warfarin resistance and biosynthesis of vitamin K-dependent blood ..
  70. Rennenberg R, de Leeuw P, Kessels A, Schurgers L, Vermeer C, van Engelshoven J, et al. Calcium scores and matrix Gla protein levels: association with vitamin K status. Eur J Clin Invest. 2010;40:344-9 pubmed publisher
    ..Carboxylated matrix Gla protein (cMGP) inhibits vascular calcification. Vitamin K is an essential cofactor for the activation of uncarboxylated matrix Gla protein (ucMGP)...
  71. Pengo V, Denas G, Jose S, Pengo M. Cancer prevention and vitamin K antagonists: an overview. Thromb Res. 2010;125 Suppl 2:S103-5 pubmed publisher
  72. Eikelboom J, O DONNELL M, Yusuf S, Diaz R, Flaker G, Hart R, et al. Rationale and design of AVERROES: apixaban versus acetylsalicylic acid to prevent stroke in atrial fibrillation patients who have failed or are unsuitable for vitamin K antagonist treatment. Am Heart J. 2010;159:348-353.e1 pubmed publisher
    Many patients with atrial fibrillation (AF) at moderate or high risk for stroke are not treated with a vitamin K antagonist (VKA)...
  73. Rombouts E, Rosendaal F, van Der Meer F. Influence of dietary vitamin K intake on subtherapeutic oral anticoagulant therapy. Br J Haematol. 2010;149:598-605 pubmed publisher
    It is unclear what advice should be given to patients using vitamin K antagonists with respect to dietary vitamin K intake...
  74. Grobler C, Callum J, McCluskey S. Reversal of vitamin K antagonists prior to urgent surgery. Can J Anaesth. 2010;57:458-67 pubmed publisher
    The purpose of this article is to review the effective options for the reversal of vitamin K antagonists (warfarin and it coumarin analogues) and to help identify the option best suited for the patient requiring urgent surgery...
  75. Palareti G, Cosmi B. Bleeding with anticoagulation therapy - who is at risk, and how best to identify such patients. Thromb Haemost. 2009;102:268-78 pubmed publisher
    Anticoagulation with vitamin K antagonists (VKAs) has been shown to be effective in the prevention and treatment of thrombotic complications in various clinical settings, including atrial fibrillation (AF), venous thromboembolism (VTE), ..
  76. Booth S. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation?. Nutr Rev. 2010;68:178-81 pubmed publisher
    Numerous risk factors for instability of oral anticoagulation have been identified, including variability in vitamin K intake...