vitamin K

noun

1

: either of two naturally occurring fat-soluble vitamins essential for the clotting of blood because of their role in the production of clotting factors in the liver:

a

or vitamin K₁

-ˈkā-ˈwən 

: the vitamin C₃₁H₄₆O₂ that is produced by plants and obtained especially from green leafy vegetables (such as collards and kale)

b

or vitamin K₂

-ˈkā-ˈtü 

: the vitamin C₄₁H₅₆O₂ that is produced by bacteria (as in the intestines of animals) and obtained especially from meat and fermented foods

2

a

or vitamin K₃

-ˈkā-ˈthrē 

: menadione

b

: any of several synthetic compounds chemically related to menadione

Examples of vitamin K in a Sentence

Recent Examples on the Web

Broccoli also provides antioxidants to protect against cancer and contains fiber, vitamin K and vitamin A to aid digestion and improve bone strength. —Bethany Thayer, Detroit Free Press, 16 Nov. 2024

The vitamin K in grapes helps with blood clotting and bone health. —Heather Jones, Verywell Health, 9 Oct. 2024

When prothrombin levels are low, vitamin K may be prescribed to prevent bleeding. —Allison Herries, Verywell Health, 7 Oct. 2024

Adding too much vitamin K to your diet can reduce its effects. —Mary Choy, Verywell Health, 5 Sep. 2024

Word History

Etymology

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

First Known Use

1935, in the meaning defined at sense 1

Kids Definition

vitamin K

noun

: any of several vitamins that are needed in order for blood to clot properly

Medical Definition

vitamin K

noun

1

: either of two naturally occurring fat-soluble naphthoquinone vitamins essential for the clotting of blood because of their role in the production of clotting factors in the liver:

a

or vitamin K₁

-ˈkā-ˈwən 

: a yellow oily vitamin C₃₁H₄₆O₂ that is produced by plants and obtained especially from green leafy vegetables (such as collards and kale) and is often used to treat hypoprothrombinemia

called also phylloquinone, phytonadione

b

or vitamin K₂

-ˈkā-ˈtü 

: a pale yellow crystalline vitamin C₄₁H₅₆O₂ that is produced by bacteria (as in the intestines of animals) and obtained especially from meat and fermented foods and that typically has greater bioavailability than vitamin K₁

called also menaquinone

2

a

or vitamin K₃

-ˈkā-ˈthrē 

: menadione

b

: any of several synthetic compounds chemically related to menadione