The Vitamin K exists in various forms , all belonging to the class of naphthoquinones. The vitamin K1 , also called phylloquinone, is the natural form of vitamin K that is what we find in plants and is the main form of supply for humans. The vitamin K2 or menaquinone, is of bacterial origin and is produced by bacteria present in the human intestine, but in insufficient quantity with respect to human needs. Finally we have vitamin K3 , also called menadione, which is of synthetic origin.
The main function of vitamin K in humans is to participate in the formation of factors necessary for the coagulation process, in particular with antihemorrhagic activity . In addition, vitamin K also protects against bone fractures.
The vitamin K deficiency is very rare in humans, since it is present in many food sources in adequate amounts, which is added to that produced by intestinal bacteria. Its deficiency may be due to liver disease and pathologies of the gastrointestinal tract or to the intake of certain drugs and involves a deficiency in coagulation and bleeding factors, but also an increased risk of fractures.
An excess of vitamin K is very rare and can result from overuse of vitamin K supplements leading to vomiting, thrombosis and excessive sweating. Let’s now see what its functions are.
Vitamin K: recommended daily amount
In 2017, a group of experts from EFSA (European Food Safety Authority) decided to maintain the reference value proposed by the Scientific Committee for Food (SCF) in 1993, i.e. that of 1 μg of phylloquinone per kg of body weight. per day, and this is valid for all ages and for both genders.
Adequate intakes (AI) are set at 70 μg per day for all adults including pregnant and lactating women , 10 μg per day for infants aged 7 to 11 months, 12 μg per day for 3-year-olds and 65 μg per day for 15-17 year-olds. For an adult, an intake of 60 μg per day is reached, for example, by consuming only 7 g of chard or 43 g of red lettuce per day.
10 foods rich in vitamin K
The foods richest in vitamin K are mainly green leafy vegetables, starting with aromatic herbs. Let’s find out where vitamin K is found .
The herbs have the record for the amount of vitamin K contained . Dried basil , thyme and sage contain 1714.5 µg per 100 grams, followed by parsley which contains 1640 µg and dried coriander (with 1359 µg).
The type of vegetable with the highest vitamin K content is chard with 830 µg per 100 grams. Beets are rich in water and fiber , useful for stimulating intestinal transit and giving satiety. They are also remineralizing, diuretic and even antioxidants, thanks to the presence of carotenoids.
The kale belongs to the family Cruciferae , such as broccoli and cabbage, which also have a very good vitamin K content . These vegetables have an important antitumor function thanks to sulforaphane and stimulate the immune system due to the presence of vitamin C. The only precaution is to use short cooking so as not to disperse these fundamental substances.
The dandelion , plant belonging to the Asteraceae family, is also known as dandelion . Its most important function is certainly the diuretic and purifying one . Its flowers have an intense yellow color.
The spinach are vegetables rich in vitamin K and folic acid , whose intake is especially crucial during pregnancy to prevent birth defects. They are also an important source of fiber, which regulates intestinal functions.
The chicory has digestive and diuretic . It counteracts constipation and helps to reduce bad cholesterol levels in the blood, thanks to the presence of inulin. Habitual consumption of chicory protects the liver and stimulates the immune system.
L ‘ soybean oil is rich in polyunsaturated fatty acids oil, especially of the omega-6 series, which in large quantities go to increase the inflammatory state of the organism and it is for this reason that it is advisable not to use. In addition, soybean oil is a type of refined oil, therefore it contains trans fats, which are not beneficial to the body.
The lettuce has good amount of vitamin K , particularly the red lettuce with 140.3 micrograms per 100 grams and curly lettuce with 126.3 micrograms. Lettuce is very moisturizing, thanks to the high water content, and stimulates intestinal transit, thanks to the fibers. Remineralizes and stimulates diuresis.
As well as vitamin K, rocket is rich in vitamin C, which has an antioxidant function and stimulates the immune system. It is purifying, counteracts water retention and arterial hypertension, thanks to the potassium content.
L ‘ olive oil , especially extra virgin, has a good vitamin K content and is rich in antioxidants and anti-cancer substances. Its components, in particular the type of fat, are able to increase the amount of good cholesterol and at the same time decrease the bad one.
Table of foods richest in vitamin K
We have seen what some of the foods richest in vitamin K are , now let’s consider the amounts of vitamin K of these and other foods in the following table .
|Food:||vitamina K / 100gr:|
|Dried basil||1714 µg|
|Dried coriander||1359 µg|
|Swiss chard||830 µg|
|Soybean oil||184 µg|
|Red lettuce||140 µg|
|Curly lettuce||126 µg|
|Chili pepper||107 µg|
|Romaine lettuce||102 µg|
|Olive oil||60 µg|
|Pine nuts||54 µg|
|Tuna in oil||44 µg|
|Red cabbage||37 µg|
|Fresh peas||25 µg|
Vitamin K: properties and benefits
After having seen in detail in which foods vitamin K is contained , let’s now learn more about its functions within the body.
- It has an anti-haemorrhagic function: the blood clotting process takes place with a complicated chain mechanism in which certain factors are activated. Vitamin K is responsible for activating certain factors that intervene in this process, with the ultimate function of avoiding excessive bleeding, such as when a wound is present. In particular, this process ends with the formation of fibrin, which forms a clot, blocking the flow of blood. Among the factors activated by vitamin K we remember prothrombin and factors VII, IX and X. The intake of vitamin K must be controlled in subjects who take warfarin, an anticoagulant that has the function of deactivating these coagulation factors. This drug is given in case of bleeding disorders, risk of thrombosis and other conditions.
- Protects from bone fractures : Vitamin K is responsible for activating a protein, called osteocalcin , which promotes the incorporation of calcium into the bone matrix, thus supporting bone metabolism. In 2006, a meta-analysis of 13 studies was published that evaluated the effect of vitamin K supplementation on fracture speed and bone density. Compared to placebo, vitamin K has been shown to reduce the risk of vertebral fractures by 60%, of hip fractures by 77% and of non-vertebral fractures by 81%;
- Improves Insulin Sensitivity : Vitamin K may improve insulin sensitivity in men with diabetes, as a study of 355 patients would seem to demonstrate .