This article is about the family of vitamers. For vitamin K1, the form most commonly used as a dietary supplement or in a multi-vitamin, see Phytomenadione.
Vitamin K
Drug class
Vitamin K structures.
Class identifiers
Use
Vitamin K deficiency, Warfarin overdose
ATC code
B02BA
Biological target
Gamma-glutamyl carboxylase
Clinical data
Drugs.com
Medical Encyclopedia
External links
MeSH
D014812
Legal status
In Wikidata
Vitamin K is a family of structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements.[1] The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ("K" from German/Danish koagulation, for "coagulation") or for controlling binding of calcium in bones and other tissues.[2] The complete synthesis involves final modification of these so-called "Gla proteins" by the enzyme gamma-glutamyl carboxylase that uses vitamin K as a cofactor.
Vitamin K is used in the liver as the intermediate VKH2 to deprotonate a glutamate residue and then is reprocessed into vitamin K through a vitamin K oxide intermediate.[3] The presence of uncarboxylated proteins indicates a vitamin K deficiency. Carboxylation allows them to bind (chelate) calcium ions, which they cannot do otherwise.[4] Without vitamin K, blood coagulation is seriously impaired, and uncontrolled bleeding occurs. Research suggests that deficiency of vitamin K may also weaken bones, potentially contributing to osteoporosis, and may promote calcification of arteries and other soft tissues.[2][4][5]
Chemically, the vitamin K family comprises 2-methyl-1,4-naphthoquinone (3-) derivatives. Vitamin K includes two natural vitamers: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone).[4] Vitamin K2, in turn, consists of a number of related chemical subtypes, with differing lengths of carbon side chains made of isoprenoid groups of atoms. The two most studied ones are menaquinone-4 (MK-4) and menaquinone-7 (MK-7).
Vitamin K1 is made by plants, and is found in highest amounts in green leafy vegetables, because it is directly involved in photosynthesis. It is active as a vitamin in animals and performs the classic functions of vitamin K, including its activity in the production of blood-clotting proteins. Animals may also convert it to vitamin K2, variant MK-4. Bacteria in the gut flora can also convert K1 into K2. All forms of K2 other than MK-4 can only be produced by bacteria, which use these during anaerobic respiration. Vitamin K3 (menadione), a synthetic form of vitamin K, was used to treat vitamin K deficiency, but because it interferes with the function of glutathione, it is no longer used in this manner in human nutrition.[2]
^"Fact Sheet for Health Professionals – Vitamin K". US National Institutes of Health, Office of Dietary Supplements. June 2020. Retrieved 26 August 2020.
^ abc"Vitamin K". Corvallis, OR: Micronutrient Information Center, Linus Pauling Institute, Oregon State University. July 2014. Retrieved 20 March 2017.
^Shearer MJ, Okano T (August 2018). "Key Pathways and Regulators of Vitamin K Function and Intermediary Metabolism". Annual Review of Nutrition. 38 (1): 127–51. doi:10.1146/annurev-nutr-082117-051741. ISSN 0199-9885. PMID 29856932. S2CID 207573643.
^ abcBP Marriott, DF Birt, VA Stallings, AA Yates, eds. (2020). "Vitamin K". Present Knowledge in Nutrition, Eleventh Edition. London, United Kingdom: Academic Press (Elsevier). pp. 137–54. doi:10.1002/9781119946045.ch15. ISBN 978-0-323-66162-1.
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VitaminK is a family of structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin...
VitaminK deficiency results from insufficient dietary vitamin K1 or vitamin K2 or both. Symptoms include bruising, petechiae, and haematoma. Vitamin...
folates) Vitamin B12 (cobalamins) Vitamin C (ascorbic acid and ascorbates) Vitamin D (calciferols) Vitamin E (tocopherols and tocotrienols) VitaminK (phylloquinones...
Vitamin K2 or menaquinone (MK) (/ˌmɛnəˈkwɪnoʊn/) is one of three types of vitaminK, the other two being vitamin K1 (phylloquinone) and K3 (menadione)...
VitaminK epoxide reductase (VKOR) is an enzyme (EC 1.17.4.4) that reduces vitaminK after it has been oxidised in the carboxylation of glutamic acid residues...
VitaminK reactions are adverse side effects that may occur after injection with vitaminK. The liver utilizes vitaminK to produce coagulation factors...
year and a life-threatening bleeding rate of 1-3% per year. Newer non-vitaminK antagonist oral anticoagulants appear to have fewer life-threatening bleeding...
VitaminK deficiency bleeding (VKDB) of the newborn, previously known as haemorrhagic disease of the newborn, is a rare form of bleeding disorder that...
Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a primary deficiency...
Vitamin D deficiency or hypovitaminosis D is a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate exposure...
symptoms of vitamin D toxicity are actually due to vitaminK depletion. One animal experiment has demonstrated that co-consumption with vitaminK reduced...
factors, VitaminK is itself oxidized. Another enzyme, VitaminK epoxide reductase (VKORC), reduces vitaminK back to its active form. VitaminK epoxide...
vitamins A, K, and C, with 122%, 1038%, and 50%, respectively, of the DV. Also having significant content in raw chard are dietary fiber, vitaminK and...
of said vitamin and prevents the symptoms of deficiency of said vitamin. Early research identified vitamins by their ability to cure vitamin-specific...
(table). It is particularly rich in vitamin C (112% DV) and vitaminK (38% DV), has a moderate content of vitamin E (10% DV), with no other micronutrients...
compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). The major natural source of vitamin D is synthesis of cholecalciferol...
including dietary fiber, 2% protein, a rich source of vitaminK, and a moderate source of B vitamins and dietary minerals. The sorbitol content of dietary...
either raw or cooked. Broccoli is a particularly rich source of vitamin C and vitaminK. Contents of its characteristic sulfur-containing glucosinolate...
lycopene, anthocyanins, lutein, and are a good source of vitamin A, vitaminK, and vitamin B6. Black carrots are one of the richest sources of anthocyanins...
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which...
of coagulopathy include anticoagulation with warfarin, liver failure, vitaminK deficiency and disseminated intravascular coagulation. Additionally, the...
(first generation) rodenticides, acting by effective blocking of the vitamin-K cycle, resulting in inability to produce essential blood-clotting factors—mainly...
used to treat certain bleeding disorders, including warfarin overdose, vitaminK deficiency, and obstructive jaundice. Use is typically recommended by...
DV) of vitamin A, vitamin C, vitaminK, magnesium, manganese, iron and folate. Spinach is a moderate source (10–19% of DV) of the B vitamins, riboflavin...
source (10–19% DV) of calcium, riboflavin, vitamin B5, folate, vitamin E, and vitaminK (table). The fat profile of raw pistachios consists of saturated...
large amount of vitaminK at 3.7 times the Daily Value (DV). It is a rich source (20% or more of the DV) of vitamin A, vitamin C, vitamin B6, folate, and...
Hypervitaminosis A refers to the toxic effects of ingesting too much preformed vitamin A (retinyl esters, retinol, and retinal). Symptoms arise as a result of...
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