vitamin K


Definition of vitamin K

1 : either of two naturally occurring fat-soluble vitamins C31H46O2 and C41H56O2 essential for the clotting of blood because of their role in the production of prothrombin

called also respectively vitamin K1\ -​ˈkā-​ˈwən How to pronounce vitamin K (audio) \, vitamin K2\ -​ˈkā-​ˈtü How to pronounce vitamin K (audio) \

2 : any of several synthetic compounds closely related chemically to natural vitamins K1 and K2 and of similar biological activity

Examples of vitamin K in a Sentence

Recent Examples on the Web Patients must also follow stricter dietary measures on warfarin, such as not eating large or inconsistent amounts of foods rich in vitamin K, which can lessen the drug's effectiveness. John Fauber And Coulter Jones, Milwaukee Journal Sentinel, 23 Aug. 2021 According to Murad, cucumber slices can combat undereye darkness, thanks to their high levels of vitamin K, which has been proven to improve blood circulation. Sophie Wirt, Allure, 3 Aug. 2021 This jibes well with Hord's observation that spinach contains plenty of vitamin K, which helps lower blood pressure and the risk of cardiovascular disease. Gregory Mcnamee, CNN, 1 July 2021 Lauren Napier's masterful formula yields a makeup wipe that smells great, feels great, and removes makeup while soothing your skin with ingredients like chamomile, pink guava (which is rich in vitamin K), and noni (packed with vitamin C). Maya Kachroo-levine, Travel + Leisure, 11 June 2021 For mild chemical exfoliation, try M-61’s Powerglow Peel squares, which are presoaked with glycolic and salicylic acids, as well as acne-scar-healing vitamin K and skin-tone-evening bilberry extract, and are gentle enough for daily use. Lauren Valenti, Vogue, 3 May 2021 Hartman agrees that both patients and doctors should jump on any swelling and bruising as soon as possible with a combo of ice packs, arnica, vitamin K, or bromelain. Kaitlin Clark, Allure, 14 Apr. 2021 Dandelions contain 112% daily value of vitamin A and 535% daily value for vitamin K, as the meme claims. Mckenzie Sadeghi, USA TODAY, 30 Mar. 2021 In juice form, the fiber is removed, but other nutrients remain; celery is a fantastic source of calcium, vitamin A, vitamin C, vitamin K and potassium. Laura Wheatman Hill,, 20 Mar. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vitamin K.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of vitamin K

circa 1935, in the meaning defined at sense 1

History and Etymology for vitamin K

from the initial letter of Danish & Swedish koagulation coagulation, Norwegian koagulasjon & German Koagulation

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Time Traveler for vitamin K

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The first known use of vitamin K was circa 1935

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Dictionary Entries Near vitamin K

vitamin H

vitamin K

vita nuova

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Statistics for vitamin K

Last Updated

31 Aug 2021

Cite this Entry

“Vitamin K.” Dictionary, Merriam-Webster, Accessed 20 Sep. 2021.

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More Definitions for vitamin K

vitamin K


Medical Definition of vitamin K

1 : either of two naturally occurring fat-soluble vitamins that are essential for the clotting of blood because of their role in the production of prothrombin in the liver and that are used in preventing and treating hypoprothrombinemia and hemorrhage:
a : a yellow oily naphthoquinone C31H46O2 that is obtained especially from alfalfa or made synthetically and that has a fast, potent, and prolonged biological effect, is effective orally, and is useful especially in treating hypoprothrombinemia induced by anticoagulant drugs

called also phylloquinone, phytonadione, vitamin K1

— see mephyton
b : a pale yellow crystalline naphthoquinone C41H56O2 that is obtained especially from putrefied fish meal and is synthesized by various bacteria (as in the intestines of humans and higher animals) and that is much more unsaturated than vitamin K1 and slightly less active biologically

called also menaquinone, vitamin K2

2 : any of several synthetic compounds that are closely related chemically to vitamins K1 and K2 but are simpler in structure and that have similar biological activity especially : menadione


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