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Vitamin K

Last updated date: 16th May 2024
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Vitamin K belongs to a collection of fat-soluble vitamins that are present in foods and sold as dietary supplements. Vitamin K is needed by the human body for the post-synthesis alteration of some proteins which are essential for blood coagulation (K from koagulation, Danish meaning "coagulation"- blood clotting vitamin) or calcium attachment in bones as well as other tissues.

The final alteration of these so-called "Gla proteins" through the enzyme gamma-glutamyl carboxylase, which utilizes vitamin K like a cofactor, finishes the production. Vitamin K deficiency is indicated by the presence of uncarboxylated proteins. They may attach (chelate) calcium ions through the process called carboxylation, something they couldn't do before.

Blood coagulation is severely hampered without vitamin K, resulting in uncontrollable bleeding. Vitamin K shortage can however weaken bones, possibly leading to osteoporosis, which encourages calcification of arteries as well as other soft tissues, according to an analysis.

Vitamin K is made up of 2-methyl-1,4-naphthoquinone (3-) derivatives chemically. Vitamin K is made up of two natural vitamers: phylloquinone (phylloquinone) and vitamin K12 (menaquinone). Vitamin K2, on the other hand, is composed of a variety of chemical subtypes of varying carbon side chains composed of isoprenoid atom groups. Menaquinone-4 (MK-4) and menaquinone-7 seem to be the two frequently reported (MK-7).


Vitamin K belongs to a collection of fat-soluble vitamins that are present in foods and sold as dietary supplements. The term "vitamin K" refers to a group of chemical compounds. These have a quinone ring in common, but they vary in the length and saturation of the carbon tail, as well as the number of repeated isoprene units throughout the side chain. Vitamin K1 is mostly found in plant sources. Vit K2 is mostly used in animal products. Vitamin K serves as an essential nutrient ingested from food, a substance synthesised and sold as a multivitamin or single-vitamin dietary supplement, and a prescription drug for particular purposes.

Vitamin Deficiency

Vitamin K deficiency is described as a vitamin-responsive inability of prothrombin, the precursor protein to the enzyme thrombin, to transform glutamate amino acids to gamma-carboxyglutamate amino acids, that has the functional effect of raising prothrombin time – a calculation of blood clotting activity – which, in extreme cases, may lead in external or internal bleeding.

Vitamin K is normally not in short supply in most people's diets. As a result, primary impairment in healthy individuals is rare. Infants, but on the other hand, seem to be at risk of deficiency irrespective of the mother's vitamin level throughout pregnancy and breastfeeding, due to inadequate vitamin transport to the placenta and insufficient vitamin levels in breast milk.

Secondary problems can result in people consuming sufficient quantities but have malabsorption disorders including chronic pancreatitis or cystic fibrosis, as well as in people who might have liver disease or damage, including alcoholic liver disease. 

Secondary vitamin K deficiency can however happen in individuals who consume a vitamin K antagonist drug like warfarin on a regular basis. Cefamandole is a medication linked to an elevated risk of vitamin K deficiency, even though the mechanism is unclear.

Use of Vitamin k

The use of vitamin k have been stated below:

  • Vitamin Deficiency in Newborns is Treated.

Vitamin K is supplied to newborns in form of an injection to avoid bleeding caused by vitamin K deficiency. Newborn babies' blood clotting parameters were approximately 30–60 per cent of adult values; which tends to be due to inadequate vitamin transport through the placenta, resulting in low foetal plasma vitamin K.

Vitamin K deficiency bleeding occurs in 0.25–1.7 per cent of infants during the first week of life, with an incidence of 2–10 cases per 1,00,000 births. Vitamin K1 levels in human milk vary from 0.85 - 9.2ηg/L (median 2.5ηg/L), whereas infant formula comprises 24 - 175ηg/L. Exclusive breastfeeding can result in late-onset bleeding, which can occur 2 to 12 weeks after giving birth when no preventive care was given. Infants that did not obtain prophylaxis at or immediately after birth used to have a late-onset rate of 35 cases per 1,00,000 live births. In comparison to the Caucasian population, Asians experience higher vitamin K deficiency bleeding.

  • Managing Warfarin Therapy

The anticoagulant drug warfarin is used to prevent blood clotting. It works by inhibiting an enzyme responsible for reforming vitamin K into a usable state. As a result, proteins that should be changed by vitamin K, such as proteins needed for blood clotting, really aren't, and therefore are not functional.

  • Treating Rodenticide Poisoning

Coumarin is a precursor reagent used throughout the pharmaceutical industry to make a variety of synthetic anticoagulant pharmaceuticals. 4-hydroxycoumarins, for example, are vitamin K antagonists. They prevent vitamin K from being regenerated and recycled. Few chemicals in the 4-hydroxycoumarin anticoagulant class were engineered to also have great potency and prolonged residence periods in the body, and they're used as second-generation rodenticides ("rat poison"). Internal haemorrhaging typically causes death after quite a period of few days to two weeks.

  • Methods of Assessment

A coagulation assay, named, Prothrombin time, was used as a vitamin K status indicator in the past, but somehow it lacks the sensitivity and specificity required for such a procedure. A most widely used indicator of vitamin K status is serum phylloquinone. Deficiency is shown by concentrations less than 0.15g/L. The other vitamin K vitamers are excluded, as well as intervention from current food intake. The gamma-carboxylation of particular glutamic acid residues inside the Gla domain of the 17 vitamin K–dependent proteins requires vitamin K.

  • Side Effects

Since there is no known toxicity related to high oral doses of vitamin K1 or (vitamin K2), regulatory bodies from Japan, the United States, and the European Union agree that almost no tolerable upper intake levels are needed. When administered intravenously, nevertheless, vitamin K1 has indeed been linked to serious side effects including cardiac arrest and bronchospasm. The reaction is classified as a nonimmune-mediated anaphylactoid reaction, with a 3 per 10,000 treatment occurrence rate. When polyoxyethylated castor oil has been used as a solubilizing agent, the maximum of reactions happens.

FAQs on Vitamin K

Q1. Name Some Vitamin k Foods.

Ans. Below mentioned are the name of some vitamin k foods:

  • Vegetables including cauliflower, broccoli, Brussels sprouts, and cabbage.

  • Fish, meat, liver, cereals, and eggs(contain smaller amounts) foods high in vitamin k.

  • Green leafy vegetables, including spinach, kale, collards, turnip greens, mustard greens, Swiss chard, romaine, parsley, and green leaf lettuce.

Q2. Specify the Forms of Vitamin K.

Ans. Below mentioned are the forms of Vitamin K:

  • Vitamin K1: Phylloquinone can be present in a variety of foods, including vegetable oils, green leafy vegetables, and milk products.

  • Vitamin K2: Menaquinone is produced by gut bacteria.

  • Vitamin K3: Menadione seems to be a water-soluble synthetic version of K3 which is no longer included in medicine due to its potential to induce hemolytic anaemia.