Vitamin K is a fat-soluble vitamin that plays a central role in blood clotting. It helps the body stop bleeding by supporting the production of proteins that regulate blood clotting. In addition, vitamin K is also important for bone health and regulating calcium metabolism, which helps prevent bone fractures. In this article, you will learn why vitamin K is essential, what health benefits it offers, and how to use it safely.

What is vitamin K?

Vitamin K is a fat-soluble vitamin that exists in two main forms: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) . Vitamin K1 is found mainly in green leafy vegetables, while vitamin K2 is found in fermented foods and animal products. Both forms play a crucial role in the activation of proteins responsible for blood clotting and calcium metabolism. Vitamin K is essential for bone health and cardiovascular health [1].

In addition to the names vitamin K1 and vitamin K2, there are other subforms of vitamin K, such as menaquinone-4 (MK-4) and menaquinone-7 (MK-7) , which have different biological half-lives and are found in different foods. Vitamin K is also called the coagulation vitamin because it is essential for blood clotting [2].

Vitamin K exists in two main forms, each of which serves different functions in the body: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone). Vitamin K1 is found primarily in green leafy vegetables like spinach and kale and is important for blood clotting, preventing excessive bleeding. In contrast, vitamin K2, which is divided into several subtypes (MK-4 to MK-13), is found more in fermented foods and animal products. It is known for its role in bone and heart health, regulating calcium by directing it to the bones and teeth while preventing plaque buildup in the arteries. Both forms are fat-soluble, meaning they rely on dietary fats for optimal absorption. Together, they contribute to overall health, although each form performs specific roles in the body.

Vitamin K1 occurs naturally in green leafy vegetables such as spinach, kale and broccoli. Vitamin K2, on the other hand, is produced by gut bacteria and is found in fermented foods such as natto (fermented soybeans) as well as animal products such as cheese and eggs. Since vitamin K is fat-soluble, it is better absorbed when consumed with fat sources [3].

Vitamin K1 is derived from plants, while vitamin K2 is produced either by fermentation or by synthesis in animal products. In dietary supplements, vitamin K2 is often used as menaquinone-7 (MK-7) because this form has a longer half-life in the body and is more bioavailable than other forms [4].

Health Benefits of Vitamin K

The most important health benefit of vitamin K is its role in blood clotting. Vitamin K activates proteins responsible for the production of blood clotting factors. Without enough vitamin K, the body cannot produce blood clotting factors, which can lead to excessive bleeding or bruising. People with a vitamin K deficiency are at increased risk for bleeding disorders, which is why vitamin K is crucial for maintaining normal blood clotting [5].

Vitamin K plays a key role in bone health by supporting the activation of osteocalcin, a protein that deposits calcium into the bone matrix. Vitamin K deficiency can lead to reduced bone density and increase the risk of bone fractures. Studies show that adequate intake of vitamin K2 can help improve bone health and reduce the risk of osteoporosis, especially in older people [6].

Vitamin K is also important for heart health because it helps prevent calcium deposits in the arteries. A deficiency in vitamin K can lead to hardening of the arteries (atherosclerosis) because calcium can build up in the blood vessels. Vitamin K2, particularly the form MK-7, has been shown to be effective in reducing calcification of the arteries and maintaining the elasticity of blood vessels, which reduces the risk of cardiovascular disease [7].

Recent studies suggest that vitamin K may also play a role in supporting brain function. It is thought that vitamin K has neuroprotective properties and could reduce the risk of neurodegenerative diseases such as Alzheimer's. These benefits may be due to vitamin K's antioxidant properties and its role in regulating inflammatory processes in the brain [8].

Vitamin K is also used to support skin health, particularly in healing wounds and reducing scars. It is often used in topical creams to treat bruises, stretch marks, and redness. Vitamin K can help improve blood circulation and speed up skin healing processes [9].

How does vitamin K work in the body?

Vitamin K works in the body by supporting the activation of proteins necessary for blood clotting, calcium metabolism and bone health. It helps transport calcium from the blood to the bones while preventing calcium deposition in the arteries. In addition, vitamin K supports normal cell function and acts as an antioxidant that protects cells from damage [10].

Recommended dosage and use of vitamin K

The recommended daily allowance (RDA) of vitamin K is about 120 micrograms per day for men and 90 micrograms per day for women. Pregnant and breastfeeding women do not have an increased need. When taking vitamin K supplements to support bone health or prevent arteriosclerosis, higher doses of vitamin K2 (MK-7) are often recommended, which can range from 100 to 200 micrograms per day [11].

Vitamin K should ideally be taken with a meal containing fat, as it is fat-soluble and requires fats to be properly absorbed. Vitamin K supplements are available in the form of capsules, drops, and tablets. It is important to consume vitamin K regularly to support blood clotting and bone health [12].

Side effects and safety of vitamin K

Vitamin K is considered safe and well-tolerated when taken in recommended amounts. Because it is a fat-soluble vitamin, it can be stored in the body, but there are no reports of toxic effects from excessive intake of vitamin K1 or K2 from food. However, people taking blood-thinning medications such as warfarin should monitor their vitamin K intake, as vitamin K may interfere with the effectiveness of these medications [13].

Rare side effects of vitamin K supplements include stomach upset or skin reactions. People taking blood thinners should consult their doctor before taking vitamin K supplements, as high vitamin K intake can affect blood clotting. It is recommended to always consult a doctor before taking vitamin K supplements, especially if there are health concerns [14].

Vitamin K compared to other fat-soluble vitamins

Both vitamin K and vitamin D are fat-soluble vitamins that play an important role in calcium metabolism and bone health. While vitamin D promotes the absorption of calcium in the intestines, vitamin K helps to deposit calcium in the bones and prevent plaque buildup in the arteries. These two vitamins work synergistically and are often used together in supplements to support bone health [15].

Vitamin K and vitamin E are both fat-soluble vitamins with antioxidant properties. While vitamin K is mainly responsible for blood clotting and calcium metabolism, vitamin E protects cell membranes from oxidative damage. Both vitamins are important for general health, but they work in different ways in the body. Vitamin E has no direct effect on blood clotting, which is why it can be taken together with vitamin K without interfering with its function [16].

Natural Sources of Vitamin K

Vitamin K1 is found mainly in green leafy vegetables such as spinach, kale, broccoli and Brussels sprouts. Vitamin K2, on the other hand, is found in fermented foods such as natto, sauerkraut and cheese, as well as in animal products such as eggs and chicken. To ensure adequate vitamin K intake, a balanced diet with a variety of green vegetables and fermented foods should be considered [17].

Vitamin K in dietary supplements

Vitamin K supplements are available in a variety of forms, including capsules, drops, and tablets. Vitamin K2 (particularly MK-7) is often preferred because it has a longer half-life in the body and is more bioavailable. This form of vitamin K is often used to support bone health and prevent hardening of the arteries. It is important to discuss taking vitamin K supplements with a doctor, especially if you are taking blood-thinning medications [18].

Final Thoughts on Vitamin K

Vitamin K is an essential fat-soluble vitamin that is vital for blood clotting, bone health and heart function. It helps store calcium in the bones and prevents calcium buildup in the arteries. For people looking to promote their bone health, support blood clotting or protect heart health, vitamin K is a valuable supplement that can be obtained either through diet or supplements.

references

[1] Examine.com. Vitamin K (Phylloquinone and Menaquinone). Available at: https://examine.com/supplements/vitamin-k/
[2] WebMD. Vitamin K - Uses and Benefits. Available at: https://www.webmd.com/vitamins/ai/ingredientmono-983/vitamin-k
[3] Healthline. Vitamin K: Benefits, Uses, and Side Effects. Available at: https://www.healthline.com/nutrition/vitamin-k
[4] Examine.com. Vitamin K Forms and Bioavailability. Available at: https://examine.com/supplements/vitamin-k/
[5] Mayo Clinic. Vitamin K for blood clotting. Available at: https://www.mayoclinic.org/drugs-supplements-vitamin-k/art-20363472
[6] National Institutes of Health. Vitamin K and Bone Health. Available at: https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
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[8] Healthline. Vitamin K and Brain Function. Available at: https://www.healthline.com/nutrition/vitamin-k-brain-health
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[11] Healthline. Vitamin K dosage and usage. Available at: https://www.healthline.com/nutrition/vitamin-k-dosage
[12] Mayo Clinic. Vitamin K Supplements and Timing. Available at: https://www.mayoclinic.org/drugs-supplements-vitamin-k/art-20363472
[13] WebMD. Vitamin K Safety and Side Effects. Available at: https://www.webmd.com/vitamins/ai/ingredientmono-983/vitamin-k
[14] Healthline. Vitamin K side effects. Available at: https://www.healthline.com/nutrition/vitamin-k-side-effects
[15] Examine.com. Vitamin K vs. Vitamin D. Available at: https://examine.com/supplements/vitamin-d/
[16] Examine.com. Vitamin K vs. Vitamin E. Available at: https://examine.com/supplements/vitamin-e/
[17] National Institutes of Health. Natural Sources of Vitamin K. Available at: https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
[18] Healthline. Vitamin K Supplement Benefits. Available at: https://www.healthline.com/nutrition/vitamin-k-supplements