If you are passionate about supplementation, you probably know the main vitamins and minerals needed to stay in great health. This is why our article may surprise you; did you know that there were two types of vitamin K?
Unknown to many, vitamin K2 is a nutrient found in fermented and animal foods. This molecule combines the renowned pro-coagulant actions of vitamin K with several positive effects on both bone and cardiovascular health. Read on if you're curious to learn more!
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- 2 Key Facts
- 3 Our Selection: The Best Vitamin K2 Supplements
- 4 Shopping Guide: Everything You Should Know About Vitamin K2
- 5 Buyer's Guide
- 6 Summary
- Vitamin K has two variants, known as vitamin K1 and K2.
- Vitamin K2 may prevent calcium deposits in the arteries and promote bone mineralisation, maintaining cardiovascular health and bone strength.
- There are various factors to evaluate before purchasing a vitamin K2 supplement. These include your dietary needs, the molecular variant of the vitamin, and the expiration date of the supplement, among others.
Our Selection: The Best Vitamin K2 Supplements
Are you ready to reap all the benefits of vitamin K2 supplements? You have come to the right place. In the section below, we have selected some of the best products currently available out there. Praised for their efficacy and value for money, they are safe to use and will allow you to make the most of vitamin K2. All you have to do is choose the supplement that best suits your needs!
Shopping Guide: Everything You Should Know About Vitamin K2
Vitamin K2 is a little-known fat-soluble vitamin that was considered inseparable from its counterpart – vitamin K1 – for decades. This variant, however, stands out for its potential influence on the body's calcium deposit. In that regard, it helps deposit this mineral is in the bone rather than the arteries, preventing the deterioration of the cardiovascular system.
What is vitamin K2 exactly?
In addition, menaquinone acts as a molecule capable of signaling and transmitting messages between different cells in the body. This is why experts believe that vitamin K2 can also be considered a hormone with stabilising and antioxidant functions (2, 3). Here is a list of more virtues attributed to this menaquinone (4):
- Activation of coagulation: Vitamin K2 promotes the blood clotting process, although with less intensity than other variants of this vitamin (vitamin K1).
- Bone formation: Menaquinone contributes to the activation of the proteins required to form the bone matrix, an essential component of healthy bone (5).
- Neuronal health: We know today that there are high levels of this vitamin in healthy brain tissue. Certain diseases, such as Parkinson's or multiple sclerosis, show low levels of menaquinone. Thus, there have been several hypotheses regarding the role of vitamin K2 in neuronal health.
- Cellular antioxidant: This molecule may have antioxidant functions similar to those of vitamin E. These include slowing down premature aging, both internally (kidney, liver, and heart damage) and externally (appearance of wrinkles and blemishes).
- Control of the immune response: Vitamin K2 could regulate the production of immune system cells or white blood cells, preventing their excessive activation in healthy individuals. As you may know, a hyperfunction of the immune system can lead to various intolerances or autoimmune diseases.
- Regulation of metabolism: Various hypotheses link vitamin K2 to the production of insulin by the pancreas and the regulation of cholesterol synthesis. This would have a positive impact on the body, helping to keep hyperglycemia and excessive cholesterol levels at bay.
- Bone mineralisation: Older adults who consume a sufficient dose of vitamin K2 have had better bone quality and strength compared to menaquinone-deficient individuals.
- Maintenance of cardiovascular health: Vitamin K2 may hamper certain processes of arterial degeneration related to the development of atherosclerosis and worsening cardiovascular health.
- Strengthening of dental enamel: The effect of menaquinone on oral health is talked about, with some experts believing that this vitamin may treat or improve the symptoms of gum disease and contribute to enamel maintenance.
- Regulation of hormone production: Vitamin K2 may regulate testosterone levels in both men and women, helping to increase them in the former and lower them to normal levels in the latter.
Unfortunately, modern diets are deficient in vitamin K2. While the gut bacteria that reside symbiotically in your body can synthesise a small amount of menaquinone, any imbalance in the microbiota will expose you to a deficiency, with the potential consequences below (4, 6):
- Hematomas and wounds caused by small blows;
- Hard-to-stop bleeding;
- Very abundant menstrual bleeding in women;
- Accelerated arterial calcification, increasing the chances of suffering cardiovascular events;
- Higher incidence of injuries and fractures.
Vitamin K2 deficiency could also have severe consequences for the metabolism, neuronal health, and aging (4). However, keep in mind that studies on menaquinone are fairly recent and may be subject to change or correction in the coming years.
What is the difference between vitamin K2 and vitamin K1?
- Vitamin K1 is found in foods of plant origin, especially in the green leaves of plants such as spinach or kale. It is mainly stored in the liver and is essential for the control of blood coagulation.
- Vitamin K2 is the result of bacterial fermentation processes. This is why it is abundant in foods of animal origin (meat, eggs, and dairy products), and in fermented foods such as cheese or natto (a Japanese dish based on fermented soybeans).
In addition to that, we can also divide vitamin K2 into smaller subclasses. K2 MK-4 is mostly found in meat products, while K2 MK-7 is much more abundant in fermented dishes. The latter is the most active form of menaquinone (5), but the least common in Western-style diets.
Therefore, the term vitamin K refers to a group of vitamins that includes menaquinone and phylloquinone. In recent years, experts have started to differentiate between the two molecules, emphasising the unique functions of both. We have compared them in the table below (8):
|Vitamin K1||Vitamin K2|
|Better known as vitamin K||Up to 13 different MK subtypes|
|Commonly found in foods of plant origin||Very present in animal-based and fermented foods|
|Essential for the blood clotting process||High levels of K2 MK-4 in the brain|
|Stored in the liver||Vitamin K2 MK-7 is distributed throughout the body.|
|Involved in bone formation||Involved in blood coagulation|
|Present in proteins of cartilage tissue, tooth enamel, and male secretions||Key role in bone mineralisation, stimulation of new bone synthesis, and increase in bone strength|
|Co-factor in the creation of new proteins||Prevention of arterial calcification|
|It may preserve neuronal function.||Antioxidant effect|
While vitamin K1 mainly affects coagulation, vitamin K2 shows additional benefits, such as the prevention of arterial calcification and strengthening of bones. Menaquinone can be considered a tissue booster for postmenopausal women and older adults.
What is the RDA of vitamin K2?
|Population group||RDA (μg)|
|Babies, 0-6 months||2 μg|
|Babies, 6-12 months||2.5 μg|
|Children, 1-3 years||30 μg|
|Children, 4-8 years||55 μg|
|Adolescents, 9-13 years||60 μg|
|Adolescents, 14-18 years||75 μg|
|Adult women||90 μg|
|Pregnant women||90 μg|
|Breastfeeding women||90 μg|
|Adult men||120 μg|
Unofficial guidelines recommend that menaquinone should make up most of the recommended daily dose of vitamin K (around 100 micrograms of an adult male's diet) (10). You can reach this target by eating foods rich in vitamin K2, but you may need to take supplements if you want to monitor this ratio more closely.
How can I increase my vitamin K2 levels?
First of all, the low levels of vitamin K2 in Western diets play a major role. While this nutrient is present in meat, eggs, and dairy products, the primary sources of menaquinone are fermented products. In the following table, you can find out more about the concentration in different foods (12):
|Food||Amount of MK-4 or MK-7 (μg)|
|Nattō (100 g)||1,000|
|Chicken breast (100 g)||15|
|Beef (100 g)||7|
|Chicken liver (100 g)||7|
|Pork (100 g)||5|
|Cheddar (100 g)||5|
|Whole milk (100 ml)||1|
|Salmon (100 g)||0.35|
|Prawns (100 g)||0.35|
This table may have led you to an alarming conclusion: just about everyone should suffer from a lack of vitamin K2 – except for Japanese food lovers! Luckily for us, our intestinal microbiota synthesises a small amount of menaquinone every day, thus preventing a problematic deficit (13).
That being said, any attack on this delicate bacterial balance can lead to hypovitaminosis. This is why you should take great care of your microbiota's health. Your sensitive gut bacteria will suffer as a result of (14):
- Excessive alcohol consumption
- Excessive consumption of sweeteners
- Fat- and carbohydrate-rich diet
- Recent consumption of antibiotic treatments
What are the benefits of K2 supplements?
If you cannot drastically modify your habits or if you want to boost your health during a physically or mentally demanding period, vitamin K2 supplements are an excellent option. The scientific studies that have been published until now indicate that menaquinone products could benefit the following groups:
- Individuals with osteoporosis: The potential of vitamin K2 in the prevention and treatment of osteoporosis – a disease that predisposes to bone fractures – is currently being investigated. Menaquinone may facilitate calcium transport to the bones, strengthening them in people with deficient mineralisation levels (5, 15, 16, 17).
- Individuals with cardiovascular risk factors: Vitamin K2 may oppose arterial stiffness by preventing calcium deposition in the arteries. Research indicates that menaquinone appears to have a beneficial effect on cardiovascular health, significantly reducing the occurrence of heart disease (15, 18, 19, 20, 21).
- Individuals looking to improve their physical performance: An interesting American study found that vitamin K2's usefulness went beyond elderly people; it also seemed to increase the resistance to physical exercise in young and healthy individuals (22). There is no doubt that this promising discovery will be investigated further in the coming years.
Despite the considerable research work carried out regarding the combination of vitamin D3 and vitamin K2, the latter has been underrated for years. Its potential as a nutritional supplement on its own will require further research to confirm or disprove current hypotheses.
Have you made your decision to supplement with vitamin K2? If that's the case, pay close attention to the following section. We have delved into the main shopping criteria to help you purchase the most suitable product for your needs. If you take them into account, we guarantee you will be on the right path to finding an efficient and affordable vitamin K2 supplement.
Vegan & Vegetarian Diet
D3 and K2 complex supplements are very difficult to adapt to the vegan diet, but menaquinone-based supplements tend to be vegan-friendly. Either way, don't forget to look for a vegan seal of approval on the label and pay attention to the components of the capsules. They should consist of cellulose rather than animal gelatin.
Allergies & Intolerances
There have been very few reports of adverse reactions in relation to vitamin K2 supplements. Most of these intolerances are related to the content of excipients, which may include gluten and lactose. This is why you should always check the product's ingredient list if you are an allergy-prone individual.
The supplements currently available on the market will contain either of the two molecular variants of vitamin K2 (MK-4 and MK-7), or a combination of both. Although MK-4 is considered to be the more active form, MK-7 seems to have a more significant effect on bone tissue. This naturally raises questions about the most efficient variant for supplementation.
Thus far, there has been no consensus on which isoform of vitamin K2 is best suited for use in supplements. Some nutritional experts recommend opting for products with both MK-4 and MK-7, combining the potency of the former with the mineralising properties of the latter.
There is little doubt that vitamin K2 is a resource with incredible and untapped potential. Its existence was denied for many years or only accepted in conjunction with other similar vitamins. Today, menaquinone has proven to be a tremendously useful substance on its own.
Vitamin K2 supplements can be a turning point for people seeking to boost their bone and artery health. In addition, a menaquinone-based product may increase the stamina of active individuals, not to mention its antioxidant power!
We hope that you enjoyed our guide on vitamin K2. If so, feel free to share it on your social media and leave us a comment below.
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