Foods containing vitamin K: what are they? Here are the richest foods

• Recommended daily amount
• Top 10 foods richest in vitamin K
• Table of vitamin K in foods
• Main properties and functions

Vitamin K is part of the fat-soluble vitamins, i.e. those vitamins that are soluble in a fatty medium and therefore need a transporter to carry them through the blood.

Vitamin K exists in several forms, all belonging to the naphthoquinone class. There vitamin k1, also called phylloquinone, is the natural form of vitamin K which is found in plants and represents the main form of supply for humans. Vitamin k2, or menaquinone, is of bacterial origin and is produced by bacteria present in the human intestine, but in insufficient quantities compared 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.

Vitamin K deficiency is very rare in humans, as it is present in numerous food sources in adequate amounts, in addition to that produced by intestinal bacteria. Its deficiency may be due to liver diseases and pathologies of the gastrointestinal tract or to the intake of certain drugs and implies a deficiency in coagulation and bleeding factors, but also an increased risk of fractures.

An excess of vitamin K is very rare and may be the result of the abuse of vitamin K supplements causing vomiting, thrombosis and excessive sweating. Let us now see what its functions are.

Vitamin K: recommended daily allowance

In 2017, a group of EFSA (European Food Safety Authority) experts decided to maintain the reference value proposed by the Scientific Committee on Nutrition (SCF) in 1993 which is 1 μg of phylloquinone per kg of body weight per day, and this is valid for all ages and for both sexes.

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 children aged 3 years, and 65 μg per day for children aged 15 to 17 years. For an adult, an intake of 60 μg per day is reached, for example, by consuming only 7 g of Swiss chard or 43 g of red lettuce per day.

10 foods rich in vitamin K

Foods rich in vitamin k are mainly green leafy vegetables, starting with aromatic herbs. Let's find out where vitamin k is found.

1 Herbs

Herbs hold the primacy for the amount of vitamin K content. Dried basil, thyme and sage contain 1714.5 µg per 100 grams, followed by parsley containing 1640 µg and dried coriander (with 1359 µg).

2 Swiss chard

The type of vegetable with the highest vitamin K content is Swiss 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 antioxidant, thanks to the presence of carotenoids.

3 green cabbage

Green cabbage belongs to the Cruciferae family, like broccoli and cabbage, which also have an excellent vitamin K content. These plants 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.

4 Dandelion

Dandelion, a plant belonging to the Asteraceae family, is also known as dandelion. Its most important function is undoubtedly that of a diuretic and depurative. Its flowers have an intense yellow color.

5 Spinach

Spinach is a vegetable rich in vitamin K and folic acid, whose intake is essential especially during pregnancy to prevent fetal malformations. It is also an important source of fiber, which regulates intestinal functions.

6 Chicory

Chicory has digestive and diuretic properties. It counteracts constipation and helps reduce bad cholesterol levels in the blood, thanks to the presence of inulin. Regular consumption of chicory protects the liver and stimulates the immune system.

7 Soybean oil

Soybean oil is an oil rich in polyunsaturated fatty acids, especially of the omega 6 series, which in large quantities will increase the inflammatory state of the organism and that is why its use is not recommended. In addition, soybean oil is a type of refined oil, so it contains trans fats, which are not beneficial for the body.

8 Lettuce

Lettuce has good vitamin K characteristics. In particular, red lettuce with 140.3 µg per 100 grams and curly lettuce with 126.3 µg. Lettuce is very moisturizing, thanks to its high water content, and stimulates intestinal transit, thanks to its fibers. It remineralizes and stimulates diuresis.

9 Arugula

In addition to vitamin K, arugula is rich in vitamin C, which has an antioxidant function and stimulates the immune system. It is depurative, counteracts water retention and high blood pressure, thanks to its potassium content.

10 Olive oil

Olive oil, particularly extra virgin olive oil, has a good vitamin K content and is rich in antioxidant and anticarcinogenic 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 rich in vitamin k, now let us consider the amounts of vitamin K of these and other foods in the following table.

Vitamin K: properties and benefits

Having seen in detail in which foods vitamin K is contained, let us now learn more about its functions within the body.

• It has antihemorrhagic function: the process of blood coagulation takes place with a complicated chain mechanism in which certain factors are activated. Vitamin K is responsible for activating certain factors involved in this process, with the ultimate function of preventing excessive bleeding, such as when there is a wound. In particular, this process ends with the formation of fibrin, which forms a clot that blocks blood flow. Among the factors activated by vitamin K, we recall prothrombin and factors VII, IX and X. Vitamin K intake must be controlled in subjects taking warfarin, an anticoagulant that has the function of deactivating these coagulation factors. This drug is administered in case of bleeding disorders, risk of thrombosis and other conditions. In this case, vitamin K may interfere with the anticoagulant effect of the drug, so care should be taken not to introduce too much vitamin K in the diet;
• Protects against bone fractures. Vitamin K is responsible for activating a protein, called osteocalcin, which promotes the incorporation of calcium into the bone matrix, thus promoting bone metabolism. In 2006, a meta-analysis of 13 studies evaluating the effect of vitamin K supplementation on fracture rate and bone density was published. Compared to placebo, vitamin K has been shown to reduce the risk of vertebral fractures by 60%, hip fractures by 77% and non-vertebral fractures by 81%;
• Improve insulin sensitivity: Vitamin K can improve insulin sensitivity in men with diabetes, as a study in 355 patients appears to show.

Do you eat enough leafy green vegetables to fill up on vitamin K?