It is used to treat certainbleeding disorders,[7] includingwarfarin overdose,vitamin K deficiency, andobstructive jaundice.[7] Use is typically recommended by mouth, intramuscular injection orinjection under the skin.[7] When given by injection benefits are seen within two hours.[7] It is also recommended for preventing and treatingvitamin K deficiency bleeding in infants.[7] Many countries in the world choose intramuscular injections in newborn to keep them safe from vitamin K deficiency bleeding. It is considered a safe treatment and saves many children from death and severe neurologic deficit every year.[9]
Side effects when given by injection may include pain at the site of injection.[7] Severeallergic reactions may occur when it is injected into a vein or muscle, but this has mainly happened when large doses of a certain type of supplement containingcastor oil were given intravenously.[10] Use during pregnancy is considered safe,[11] use is also likely okay duringbreastfeeding.[12] It works by supplying a required component for making a number ofblood clotting factors.[7] Food sources includegreen vegetables, vegetable oil, and some fruit.[13]
Vitamin K is a fat-soluble vitamin that is stable in air and moisture but decomposes in sunlight.[17] K1 is apolycyclicaromaticketone, based on 2-methyl-1,4-naphthoquinone, with a 3-phytylsubstituent. It is found naturally in a wide variety of green plants, particularly in leaves, since it functions as an electron acceptor duringphotosynthesis, forming part of the electron transport chain ofphotosystem I.[18][19]
The best-known function of vitamin K in animals is as a cofactor in the formation ofcoagulation factors II (prothrombin), VII, IX, and X by the liver. It is also required for the formation of anticoagulant factors protein C and S. Vitamin K is required for bone protein formation.
In terms of distribution, phylloquinone typically occurs in higher levels in the liver, heart and pancreas, but in lower levels in the brain, kidneys, and lungs.[20]
The biosynthesis of vitamin K1 via the transformation of chorismate occurs in nine steps.
Vitamin K1 is synthesized from chorismate, a compound produced from shikimate via the shikimate pathway. The conversion of chorismate to vitamin K1 comprises a series of nine steps:[22][23][24]
Chorismate isisomerized to isochorismate by isochorismate synthase, or MenF (menaquinone enzyme).
Addition of 2-oxoglutarate to isochorismate by PHYLLO, a multifunctional protein comprising three different enzymatic activities (MenD, H, and C).
Elimination of pyruvate by PHYLLO.
Aromatization to yield o-succinyl benzoate by PHYLLO.
O-succinylbenzoate activation to corresponding CoA ester by MenE.
Naphthoate ring formation by naphthoate synthase (MenB/NS).
Thiolytic release of CoA by a thioesterase (MenH).
Attachment of phytol chain to the naphthoate ring (MenA/ABC4).
Methylation of the precursor at position 3 (MenG).
^abcdefghijk"Phytonadione". The American Society of Health-System Pharmacists.Archived from the original on 29 December 2016. Retrieved8 December 2016.
^World Health Organization (2023).The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023). Geneva: World Health Organization.hdl:10665/371090. WHO/MHP/HPS/EML/2023.02.
^Riegert-Johnson DL, Volcheck GW (October 2002). "The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review".Annals of Allergy, Asthma & Immunology.89 (4):400–406.doi:10.1016/S1081-1206(10)62042-X.PMID12392385.
^Bailey B (February 2003). "Are there teratogenic risks associated with antidotes used in the acute management of poisoned pregnant women?".Birth Defects Research. Part A, Clinical and Molecular Teratology.67 (2):133–140.doi:10.1002/bdra.10007.PMID12769509.
^"Vitamin K".Office of Dietary Supplements. U.S. National Institutes of Health. 11 February 2016.Archived from the original on 31 December 2016. Retrieved30 December 2016.
^Haroon Y, Shearer MJ, Rahim S, Gunn WG, McEnery G, Barkhan P (June 1982). "The content of phylloquinone (vitamin K1) in human milk, cows' milk and infant formula foods determined by high-performance liquid chromatography".The Journal of Nutrition.112 (6):1105–1117.doi:10.1093/jn/112.6.1105.PMID7086539.
^Basset GJ, Latimer S, Fatihi A, Soubeyrand E, Block A (2017). "Phylloquinone (Vitamin K1): Occurrence, Biosynthesis and Functions".Mini Reviews in Medicinal Chemistry.17 (12):1028–1038.doi:10.2174/1389557516666160623082714.PMID27337968.
^Reumann S (2013). "Biosynthesis of vitamin K1 (phylloquinone) by plant peroxisomes and its integration into signaling molecule synthesis pathways".Peroxisomes and their Key Role in Cellular Signaling and Metabolism. Subcellular Biochemistry. Vol. 69. Springer Netherlands. pp. 213–29.doi:10.1007/978-94-007-6889-5_12.ISBN9789400768888.PMID23821151.
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