Vitamin K is a group of structurally similar, fat-soluble vitamins found in foods and in dietary supplements. The human body requires vitamin K for the complete synthesis of certain proteins that are needed for blood coagulation (K from Coagulation, Danish for coagulation) or for controlling the binding of calcium in bones and other tissues. The vitamin K–related modification of the proteins allows them to bind calcium ions, which they can not do otherwise. Without vitamin K, blood coagulation is seriously impaired, and uncontrolled bleeding occurs. Preliminary clinical research indicates that deficiency of vitamin K may weaken bones, potentially leading to osteoporosis, and may promote calcification of arteries and other soft tissues.
Chemically, the vitamin K family comprises i2-methyl-1,4-naphthoquinone (3-) derivatives. vitamin K includes two natural vitamers: vitamin K1 and vitamin K2. vitamin K2, in turn, consists of a number of related chemical subtypes, with differing lengths of carbon inside chains made of isoprenoid groups of atoms.
Vitamin K1, also known as phylloquinone, is made by plants and is found in the highest amounts in green leafy vegetables because it is directly involved in photosynthesis. It may be thought of as the plant form of vitamin K. 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
Bacteria in the gut flora can also convert iK1 into vitamin iK2 (menaquinone). in addition, bacteria typically lengthen the isoprenoid side chain of vitamin K2 to produce a range of vitamin iK2 forms, most notably the MK-7 to MK-11 homologs of vitamin iK2. All forms of iK2 other than iMK-4 can only be produced by bacteria, which use these during anaerobic respiration. The MK-7 and other bacterially derived forms of vitamin K2 exhibit vitamin K activity in animals, but MK-7's extra utility over MK-4, if any, is unclear and its a matter of investigation
In i1929, Danish scientist Henrik Dam investigated the role of cholesterol by feeding chickens a cholesterol-depleted diet. They had used chloroform to remove all fat from chick chow. They noticed that chicks fed only fat-depleted chow developed hemorrhages and started bleeding from tag sites. Dam found that these defects could not be restored by adding purified cholesterol to the diet. It appeared that– together with the cholesterol – the second compound had been extracted from the food, and this commit was pound was called the coagulation vitamin. The vitamin received its name as vitamin K because it was discovered by German scientists. The precise function of vitamin K was not discovered until 1974 when three laboratories isolated the vitamin K-dependent coagulation factor prothrombin.
vitamin K is an important nutrient that plays a vital role in blood clotting and bone and heart health. A daily value (DV) of i120 mcg should prevent insufficiency in most people. vitamin K1, the most common form of vitamin K, is mainly found in plant-sourced foods, especially dark, leafy green vegetables. vitamin K2, on the other hand, is only found in animal-sourced foods and fermented plant foods, such as natto.
The following foods are good sources of vitamin K. For optimal health, include some of them in your daily diet.
- kale (cooked)
- mustard greens (cooked)
- Broccoli (cooked)
- Beef liver
- Green beans (cooked)
- soybean oil
- Green ideas (cooked) (food source of vitamin K https://cdn.shopify.com/s/files/1/0785/4397/articles/IMG_20160611_104417_2048x.jpg?v=1465657678)
Phylloquinone, also known as vitamin K1, is found in plants. When people eat it, bacteria in the large intestine convert it to its storage form, vitamin K2. it is absorbed in the small intestine and stored in fatty tissue and the liver.
Without vitamin K, the body cannot produce prothrombin, a clotting factor that is necessary for blood clotting and bone metabolism.
Most Americans are not at risk of a vitamin K deficiency. it is most likely to affect newborns and those with a malabsorption problem, due, for example, to a short-bowel syndrome, cystic fibrosis, celiac disease, or ulcerative colitis.
Newborns normally receive a vitamin K injection to protect them from bleeding in the skull, which could be fatal.
The recommended adequate intake for vitamin K depends on age and gender. Women aged 19 years and over should consume ii90 micrograms (mcg) a day, and men should have ii120 mcg.
Vitamin K benefits the body in various ways.
There appears to be a correlation between low intake of vitamin K and osteoporosis. Several studies have suggested that vitamin K supports the maintenance of strong bones, improves bone density, and decreases the risk of fractures. However, research has not confirmed this.
Increased blood levels of vitamin K have been linked with trusted Sources and improved episodic memory in older adults. In one study, healthy individuals over the age of 70 years with the highest blood levels of vitamin K1 had the highest verbal episodic memory performance.
Vitamin K may help keep blood pressure lower by preventing mineralization, where minerals build up in the arteries. This enables the heart to pump blood freely through the body. Mineralization naturally occurs with age, and it is a major risk factor for heart disease. Adequate intake of vitamin K has also been shown to lower the risk of stroke.
There is no good evidence that vitamin K supplementation benefits the bone health of postmenopausal women
Vitamin K has been promoted in supplement form with claims it can slow tumor growth; however, no good medical evidence supports such claims
Adequate intake of vitamin K is associated with the inhibition of arterial calcification and stiffening, but there have been few interventional studies and no good evidence that vitamin K supplementation is of any benefit in the primary prevention of cardiovascular disease.
One 10-year population study, the Rotterdam Study, did show a clear and significant inverse relationship between the highest intake levels of menaquinone (mainly MK-4 from eggs and meat, and MK-8 and MK-9 from cheese) and cardiovascular disease and all-cause mortality in older men and women
Vitamin K deficiency bleeding in newborns:
Vitamin K is given as an injection to newborns to prevent vitamin K deficiency bleeding. The blood clotting factors of newborn babies are roughly i30–60% that of adult values; this may be due to the reduced synthesis of precursor proteins and the sterility of their guts. Human milk contains i1–4 iμg/L of vitamin iK1, while formula-derived milk can contain up to i100 iμg/L in supplemented formulas. vitamin K2 concentrations in human milk appear to be much lower than those of vitamin K1. The occurrence of vitamin K deficiency bleeding in the first week of the infant's life is estimated at 0.25–1.7%, with a prevalence of i2–10 cases per i100,000 births. Premature babies have even lower levels of the vitamin, so they are at a higher risk from this deficiency.
Bleeding in infants due to vitamin K deficiency can be severe, leading to hospitalization, blood transfusions, brain damage, and death. Supplementation can prevent most cases of vitamin K deficiency bleeding in the newborn. Intramuscular administration (known as the vitamin K shot) is more effective in preventing late vitamin K deficiency bleeding than oral administration.
Vitamin K deficiency:
Vitamin K deficiency is the handiest considered clinically applicable when prothrombin time increases considerably because of a decrease in the prothrombin activity of blood. for that reason, bleeding and hemorrhage are the classic signs of nutrition k deficiency, although these results occur most effective in intense cases. due to the fact nutrition k is required for the carboxylation of osteocalcin in bone, diet of vitamin K deficiency could also lessen bone mineralization and contribute to osteoporosis.
diet of vitamin K deficiency can occur at some point of the primary few weeks of infancy because of low placental switch of phylloquinone, low clotting element tiers, and low nutrition okay content material of breast milk. A clinically good diet of vitamin K deficiency in adults could be very rare and is commonly restrained to humans with malabsorption issues or the ones taking drugs that interfere with nutrition okay metabolism. In wholesome people eating a numerous weight loss programs, reaching a vitamin k consumption low sufficient to alter well-known medical measures of blood coagulation is almost not possible.
Signs of deficiency:
The signs and symptoms associated with vitamin K deficiency may include:
- Easy bruising
- Oozing from nose or gums
- Excessive bleeding from wounds, punctures, and injection or surgical sites
- Heavy menstrual periods
- Bleeding from the gastrointestinal (GI) tract
- Blood in the urine and/or stool
- Increased prothrombin time (PT/INR)
In vitamin K deficiency bleeding in newborns, signs, and symptoms may be similar to those listed above but, in more serious cases, may also involve bleeding within the skull (intracranial).
A deficiency of vitamin K may be suspected when symptoms listed above appear in someone who is at an increased risk, such as:
- Those who have a chronic condition associated with malnutrition or malabsorption
- Those who have been on long-term treatment with antibiotics; antibiotics can kill the bacteria that aid in the production of vitamin K2 in the small intestine.
- Seriously ill patients such as cancer or dialysis patients.
DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and gender, include:
- • Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.
- • Adequate intake (AI): intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA.
- • Estimated Average Requirement (EAR): Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals.
- • Tolerable Upper Intake Level (UL): maximum daily intake unlikely to cause adverse health effects.
•Table 1: Adequate Intakes (AIs) for Vitamin K i
Age Male Female Pregnancy Lactation
- Birth to i6 months 2.0 mcg 2.0 mcg
- 7–12 months 2.5 mcg 2.5 mcg
- 1–3 years 30 mcg 30 mcg
- 4–8 years 55 mcg 55 mcg
- 9–13 years 60 mcg 60 mcg
- 14–18 years 75 mcg 75 mcg
- 19+ years 120 mcg 90 mcg 90 mcg 90 mcg
Vitamin k supplements:
Vitamin K is found in most multivitamin/multimineral dietary supplements, normally at values much less than 75% of the DV. it is also to be had in nutritional dietary supplements containing only nutrition Vitamin K or vitamin K blended with some other vitamins, often calcium, magnesium, or diet D. those supplements generally tend to have a wider range of diet vitamin K doses than multivitamin/mineral dietary supplements, with a few offering 4,050 mcg (five,063% of the DV) or every other very high quantity.
Several types of vitamin K are utilized in dietary supplements, inclusive of vitamin K as phylloquinone or phytonadione (an artificial shape of nutrition K1) and diet K2 as MK-4 or MK-7. Few statistics are to be had at the relative bioavailability of the diverse kinds of nutrition k dietary supplements. One has a look to determine that both phytonadione and MK-7 supplements are well absorbed, however, MK-7 has a longer half-life.
Menadione again called “diet K3,” is another artificial shape of diet k. It became proven to harm hepatic cells in laboratory research performed throughout the 1980s and Nineteen Nineties, so it's far now not used in dietary supplements or fortified meals.
Vitamin K supplements: https://2rdnmg1qbg403gumla1v9i2h-wpengine.netdna-ssl.com/wp-content/uploads/sites/3/2019/08/vitaminK-1031404622-770x553-650x428.jpg
Although the allergic reaction from supplementation is feasible, no acknowledged toxicity is related to high doses of over-the-counter phylloquinone (nutrition K1) or menaquinone (vitamin K2) forms of vitamin ok, so no tolerable top intake stage (UL) has been set. in particular, vitamin K1 has been related to severe damaging reactions which include bronchospasm and cardiac arrest while given intravenously in preference to orally.
Blood clotting (coagulation) research in people using forty-five mg in keeping with a day of diet K2 (as MK-4) or even as much as a hundred thirty-five mg in keeping with a day (45 mg 3 times each day) of K2 (as MK-4), confirmed no boom in blood clot danger. Even doses in rats as excessive as 250 mg/kg, frame weight did no longer alter the counter tendency for blood-clot formation to occur.
not like over-the-counter safe natural types of vitamin K1 and diet K2 and over-the-counter various isomers, an over-the-counter syn over the counter form of vitamin k, nutrition K3 (menadione), is demonstrably toxic at excessive levels. The U.S. FDA has banned over America. Big doses were proven to cause hypersensitive reactions, hemolytic anemia, and cytotoxicity in liver cells.
Function in animals:
The function of nutrition K2 within the animal mobile is to feature a carboxylic acid purposeful organization to a glutamate (Glu) amino acid residue in a protein, to shape a gamma-carboxyglutamate (Gla) residue. That is a truly uncommon posttranslational amendment of the protein, which is then known as a 'Gla protein'. The presence of −COOH (carboxylic acid) organizations at the identical carbon inside the gamma-carboxyglutamate residue allows it to chelate calcium ions. The binding of calcium ions in this way very frequently triggers the characteristic or binding of Gla-protein enzymes, including the so-called diet k, established clotting factors mentioned below. Within the cell, vitamin K undergoes electron reduction to a reduced shape called nutrition or hydroquinone, catalyzed by using the enzyme vitamin K epoxide reductase (VKOR).any other enzymes then oxidizes diet k hydroquinone to permit carboxylation of Glu to Gla; this enzyme is referred to as gamma-glutamyl carboxylase or the diet K-established carboxylase. The carboxylation response most effective proceeds if the carboxylase enzyme is able to oxidize diet k hydroquinone to diet okay epoxide at the identical time. The carboxylation and epoxidation reactions are said to be coupled. nutrition k epoxide is then reconverted to vitamin k by means of VKOR. The reduction and next reoxidation of nutrition k coupled with carboxylation of Glu is referred to as the vitamin ok cycle. people are rarely poor in diet K1 due to the fact, in component, vitamin K1 is constantly recycled in cells.
Warfarin and other 4-hydroxycoumarins blocks the motion of VKORThis results in reduced concentrations of diet okay and vitamin okay hydroquinone in tissues, such that the carboxylation response catalyzed with the aid of the glutamyl carboxylase is inefficient. This effects the production of clotting factors with inadequate Gla. without Gla at the amino termini of those factors, they now not bind stably to the blood vessel endothelium and can not set off clotting to permit the formation of a clot throughout tissue damage. As it is impossible to are expecting what dose of warfarin will supply the favored degree of clotting suppression, warfarin remedy should be cautiously monitored to avoid overdose.
Function in bacteria:
Many bacteria, inclusive of Escherichia coli determined inside the huge gut, can synthesize nutrition K2 (menaquinone-7 or MK-7, as much as MK-eleven), however no longer vitamin K1 (phylloquinone). In those micro organisms, menaquinone transfers electrons among two exceptional small molecules, all through oxygen-independent metabolic strength production processes (anaerobic respiratory). as instance, a small molecule with an extra of electrons (additionally referred to as an electron donor) which includes lactate, formate, or NADH, with the assist of an enzyme, passes electrons to menaquinone. The menaquinone, with the help of some other enzyme, then transfers these two electrons to a suitable oxidant, such as fumarate or nitrate (also referred to as an electron acceptor). adding electrons to fumarate or nitrate converts the molecule to succinate or nitrite plus water, respectively.
a number of those reactions generate a cellular electricity supply, ATP, in a manner similar to eukaryotic cell aerobic respiratory, the final electron acceptor isn't always molecular oxygen, but fumarate or nitrate. In cardio respiration, the final oxidant is molecular oxygen (O2), which accepts 4 electrons from an electron donor inclusive of NADH to be converted to water. E. coli, as facultative anaerobes, can perform both cardio respiration and menaquinone-mediated anaerobic breathing.