Best Vegan Vitamin K2 Sources

In this article, we'll discuss what vitamin K-2 is, how it can be obtained from vegan sources, what a deficiency can cause, and whether supplementation is needed.
Zeynep Ozdemir, RDN

Written by Zeynep Ozdemir, RDN. Updated on November 27, 2022.

Vitamin K is an important vitamin that plays a role in maintaining strong bones and helps blood clot. There are two distinct forms of it: K-1 and K-2.

The principal type of vitamin K is vitamin K-1, and the best sources for it are dark green leafy vegetables.

Animal-based proteins and foods that have been fermented are the primary sources of vitamin K-2.

Additionally, the bacteria that live in a person’s digestive tract create trace amounts of K-2.

In this article, we’ll discuss what vitamin K-2 is, how it can be obtained from vegan sources, what a deficiency can cause, and whether supplementation is needed.

What is Vitamin K?

Vitamin K is the name given to a group of fat-soluble vitamins that are required by the body in order to generate a protein known as prothrombin.

This protein aids in the clotting of blood and controls the metabolism of bone.

The vitamin is most often found in two different forms:

Vitamin K-1, also known as phylloquinone, is the most common form of vitamin K and may be naturally found in dark leafy green veggies, such as kale or spinach. Dietary sources are the most important way to get vitamin K.

Vitamin K-2, also known as menaquinone, may be found in fermented foods and organ meats, although only in small amounts. Vitamin K-2 is also produced by the bacteria in the gut.

The Function of Vitamin K

Both forms of vitamin K are required for the body to make prothrombin, which is a protein that is essential for maintaining healthy bone metabolism, blood clotting, and cardiovascular health.

In addition to this, vitamin K assists in the process of generating energy in the cells by their mitochondria.

The primary function of vitamin K-1 is in the process of blood coagulation. It’s possible that K-2 has a wider variety of roles throughout the body.

People who already have high blood pressure might benefit the most from increasing their vitamin K-2 consumption since it lowers their chance of developing peripheral artery disease.

However, K-1 does not influence the risk of peripheral artery disease.

Antioxidant capabilities are possessed by vitamin K. It does this by preventing a process known as peroxidation, which would otherwise cause damage to cell membranes as a result of an overabundance of free radicals.

Vitamin K’s antioxidative power may be diminished when used with some blood-thinning medications, like warfarin.

Health Effects of Vitamin K-2

Vitamin K-2 is important for the coagulation of blood and the healing of wounds, but it also has a variety of other positive effects on one’s health. We will talk about some of them below.


Vitamin K-2 may both reduce the likelihood of cardiovascular injury and enhance overall cardiovascular health.

According to research, vitamin K-2 is responsible for activating a protein that stops calcium deposits in the blood vessel walls from developing.

The author referred to research that suggested that a diet rich in the natural source of vitamin K2 may reduce the incidence of coronary heart disease.


K-2 increases optimal bone density through a bone-binding protein (carboxylated osteocalcin).

Research published in 2019 explored the impact of administering MK-4 supplements to a group of 29 postmenopausal women who had suffered from vertebral or hip compression fractures.

According to the findings, vitamin K-2 did not seem to boost the effectiveness of the osteoporosis drug in any way.

Depression and Anxiety

A person’s likelihood of acquiring depression, cognitive impairment, and anxiety may be heightened when their blood glucose levels are elevated.

According to research looking into the effects of vitamin K-2 on rats having metabolic syndrome, which is characterized by elevated blood glucose levels, feelings of anxiety and sadness, and impaired cognition.

After a course of vitamin K therapy lasting 10 weeks, the patient’s blood glucose level was regulated, and anxiety symptoms and depression were significantly decreased.

However, it could not have any positive effect on the rats’ impaired memory.


Vitamin K-2 has antioxidant characteristics, which have the potential to help fight against cancer. Furthermore, the data point to the possibility that K-2 may inhibit genetic pathways that result in the development of tumors.

The development of tumors in cells was investigated in a research that was published in 2018 and found that vitamin K-2 that had been considerably inhibited the formation of tumors.

According to the findings of research published in 2019, K-2 seems to inhibit the activity of HIF-1A in hepatocellular carcinoma cells strongly.

A high-priority target for cancer medication treatment is an enzyme called HIF-1A.

Plant-Based Sources of Vitamin K-2

When it comes to K-2 sources, the first thing that comes to mind is egg yolk, organ meats, and fermented milk products.

Since vegans do not consume these products, K-2 deficiency creates a question mark in mind.

However, there are also foods that contain vitamin K-2 that are suitable for vegan consumption:

  • Natto (a dish made with fermented soybeans that are traditional in Japan)
  • Sauerkraut
  • Kombucha (Unpasteurized)
  • Vegan kimchi
  • Plant-based kefir

In addition, intestinal bacteria have the ability to convert vitamin K-1 into vitamin K-2.

Vegan Vitamin K-1 sources include:

  • Lettuce
  • Dark green leafy vegetables, such as collards, kale, and spinach
  • Broccoli
  • Turnips
  • Blueberries
  • Grapes
  • Carrots
  • Vegetable oils

Recommend Daily Intake

According to recommendations made by the Office of Dietary Supplements (ODS), people should obtain the following daily doses of vitamin K:

Males: 120 micrograms (mcg)
Females: 90 micrograms (mcg)

However, researchers have recently come to the conclusion that the recommended daily intakes for vitamins K1 and K2 should be split.

It has been argued that the Recommended Daily Intake (RDI) for vitamin K in the majority of nations was established based on studies conducted over a century ago.

In addition, studies have shown that K-2 is more efficient than K-1. It is able to be stored in the body for a longer amount of time, it has a wider distribution area throughout tissues, and it has a greater metabolic impact.

Signs of Vitamin K-2 Deficiency

Vitamin K deficiency is characterized by several symptoms. The most prominent sign is profuse bleeding.

Excessive bleeding can not always be immediately apparent since it may happen only if the individual sustains a wound.

Other symptoms of heavy bleeding may include:

  • Prone to bruising readily.
  • Little blood clots develop beneath the fingernails.
  • Bleeding in the mucous membranes that border internal body locations.
  • Feces that are jet-black, tarry, or include blood.

When examining newborns and infants for indicators of vitamin K inadequacy, physicians will also search for:

  • The place in which the umbilical cord was removed is bleeding.
  • The occurrence of bleeding in the nose, skin, digestive system, or other areas.
  • If the infant has been circumcised, the penis will bleed.
  • Sudden cerebral bleeds are considered serious and sometimes deadly.


In order to diagnose a vitamin K deficiency in an individual, the medical history is first questioned.

The PT test, also known as the prothrombin time test, is a kind of coagulation test that the physician could do.

After collecting a little amount of blood, they mix in some chemicals and watch how long it takes for a clot to the blood.

The normal time it takes for blood to clot is between 11 and 13.5 seconds. If it takes much longer than this, it may suggest that you do not have enough vitamin K.

Before having this blood test done, it is recommended that individuals abstain from eating foods that contain high quantities of vitamin K.

Should I Supplement Vitamin K-2 on a Vegan Diet?

As a vegan, it could be difficult to receive enough vitamin K-2 from your diet. Thus, taking vitamin K-2 supplements might be a good idea in this case.

It’s probably the greatest way to make sure you’re receiving the vitamin K-2 your body needs if you don’t already consume natto on a daily basis.

Another reminder to see your physician before taking a vitamin K-2 supplement to verify that it will not interact with any medications you may be taking.

How to Choose Vitamin K Supplement to Take

The Food and Drug Administration (FDA) offers some information on vitamin K which should be taken into account if you decide to go the path of taking a vitamin K supplement.

1. Give some thought to your overall diet. Vitamin K-2 can be hard to get from food sources if you are a vegan, but there is no evidence that there is any toxicity associated with excessive dosages.

2. Consult your healthcare provider before taking any vitamin K-2 supplement since it may interact negatively with some drugs, including anticoagulants and maybe even over-the-counter medications.

3. Make sure you get your supplements from a reliable source. Because the FDA does not evaluate dietary supplements, it is up to the producers to ensure that their products are risk-free. Getting the highest possible product quality will be guaranteed for you if you purchase it from a reliable supplier.

MK-4 and MK-7 are the kind of vitamin K2 supplements that are most often seen in stores.

A study that was published in 2019 indicates that the body’s ability to absorb 10 times more vitamin K-2 in the type of MK-7 than vitamin K-1.

One of the goals of the 2020 research was to investigate the relationship between vitamin K-2 and bone mineral density.

Postmenopausal women who took a vitamin K-2 supplement at a dose of 90 micrograms per day exhibited a substantial reduction in bone loss when compared to persons who took a placebo or a lesser dosage.

This was the case even though vitamin D and calcium were not included in the study.

When vitamin D and calcium were co-supplemented with vitamin K-2, there was no discernible increase in the effects of the combination.

The quality of your vitamin K-2 consumption may also have a positive effect on your heart health.

When compared to its vitamin K-1 equivalent, vitamin K-2 may be more advantageous.

It has been discovered that K-2 has several health advantages, one of which is that it may lower the chance of developing heart disease.

Additionally, it is known that the vitamin works effectively with vitamin D, which is another fat-soluble vitamin that should be supplemented, particularly for vegans.


Vitamin K is a vitamin that is both taken in the diet and produced by the body’s bacteria. It has many roles that support the basic functioning of the body, especially blood clotting.

It exists in two forms, K-1 and K-2. Vitamin K-1 is readily available from vegan sources. In contrast, vitamin K-2 is often found in animal foods, which raises concerns about deficiency in vegans.

Symptoms of deficiency include bleeding, and a PT test can also diagnose vitamin K deficiency.

You should always consult your healthcare professional when you need supplementation support.

It is also recommended that you follow the guidelines provided by the FDA for choosing the supplement to take.

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