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, vitamin K2

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

An evaluation of a cotton pad containing vitamin K and caffeine found that the pad acted as an emollient and drastically reduced the appearance of under-eye circles. Nikhita Mahtani, CNN Underscored, "Want to fight dark circles? Look for these ingredients in your next eye cream," 10 Aug. 2019 In the first few hours of a newborn’s life, doctors administer a vitamin K shot. Renee Diresta, WIRED, "The Complexity of Simply Searching for Medical Advice," 3 July 2018 Like other vegetables, celery does contain vitamins and nutrients, such as vitamin K (which supports healthy blood clotting) and potassium (which helps support body functions like a healthy blood pressure), Larson says. Carolyn L. Todd, SELF, "Surprise: Celery Juice Will Not Cure All of Your Health Issues," 25 Jan. 2019 State officials previously have said that over-the-counter vitamin K supplements are not strong enough to treat the condition. Elvia Malagon,, "Third person dies after more than 100 sickened in tainted synthetic pot outbreak in Illinois, officials say," 9 Apr. 2018 These include calcium, magnesium, vitamin D, several B vitamins, vitamin A, vitamin K, potassium, iodine, selenium, borate, zinc, manganese, molybdenum, beta-carotene, and iron. Korin Miller, Allure, "Do You Need to Take a Multivitamin? Here's What Nutritionists Say," 3 May 2018 On Monday, officials announced a donation of nearly 800,000 vitamin K tablets to treat victims. Robert Mccoppin,, "Tests confirm Chicagoan died from poison in synthetic marijuana," 25 Apr. 2018 The treatment involves high doses of vitamin K, first intravenously, then up to 30 tablets a day for up to six months. Robert Mccoppin,, "More people sickened by synthetic marijuana believed to be tainted with rat poison," 25 June 2018 For example, dark-green vegetables provide the most vitamin K, red and orange vegetables the most vitamin A, legumes [beans and peas] the most dietary fiber, and starchy vegetables the most potassium. NBC News, "How I learned to love (or at least tolerate) vegetables," 26 Mar. 2018

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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Statistics for vitamin K

Last Updated

25 Aug 2019

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Time Traveler for vitamin K

The first known use of vitamin K was circa 1935

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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

Comments on vitamin K

What made you want to look up vitamin K? Please tell us where you read or heard it (including the quote, if possible).


readily or continually undergoing change

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