I’m sure you’ve heard of vitamin K and its role in blood clotting but did you know that this vitamin exists in two forms namely vitamin K1 (phylloquinone) and vitamin K2 (a group of compounds known as menaquinones)?
So what you may wonder. Well, vitamin K1 deficiency is rare and practically nonexistent, unlike vitamin K2 deficiency.
Unfortunately, although vitamin K2 could be the ‘missing link’ between diet and numerous fatal health conditions, it hasn’t been much in the spotlight. In this article, we’ll unravel everything you need to know about this little-known nutrient.
Top 5 health benefits of vitamin K2
1. Vitamin K2 may reduce risks of osteoporosis.
Let me ask you something: if you wanted to optimize your bone health, what would you do? Ensure that you’re getting enough dietary calcium, vitamin D and magnesium while doing some weight-bearing exercises?
That’s great; but you’d also have to add vitamin K2 (and intestinal health optimization) to that list.
You see, this fat-soluble vitamin is necessary to activate osteocalcin, a protein secreted by osteoblasts the body’s bone-building cells. Once activated, osteocalcin can pull calcium into the bones where the osteoblasts then incorporate it into the bone structure. This process ameliorates bone architecture; increases bone mass and strength while improving the bone’s collagen structure (cross-linking of fibrous tissue) to promote the formation of tough but supple bone which is less vulnerable to fractures. That’s not all; together with vitamin D3, vitamin K2 can help prevent bone loss.
In a 3-year study, post-menopausal women taking vitamin K2 supplements experienced a much slower decline in bone mineral density.
Scientists have also discovered that women living in western Japan (where the diet is lower in vitamin K2) had a significantly higher risk of hip fractures compared to those living in Tokyo where vitamin K2 rich foods are regularly consumed.
2. Vitamin K2 could keep cardiovascular diseases at bay.
New evidence has confirmed that vitamin K2 can offer protection against heart disease via the different mechanisms described below.
Did you know that about 20% of atherosclerotic plaques (from the early to the more advanced stages of heart disease) are made up of calcium?
Calcification of the arteries is a massive risk factor for heart disease and that’s where vitamin K2 comes in. By regulating calcium metabolism, vitamin K2 ensures that calcium gets deposited in the bones and teeth where it belongs and out of soft tissues like the arteries and veins where it can cause tremendous damage. Vitamin K2 also ensures that the arteries remain elastic and flexible and thus allows blood to flow easily through the body.
Vitamin K2 also tones down inflammation while preventing accumulation of lipids and white blood cells in the arteries. In other words, this vitamin can help keep heart disease at bay by reducing the risk of plaque formation which marks the debut of atherosclerosis (the hardening of arteries).
Another mechanism by which vitamin K2 can protect you against heart disease is through the activation of Matrix GLA Protein (MGP), a protein which is in charge of protecting arteries and veins against calcification.
Damage to your blood vessels – this can be caused by a diet high in sugar or an unhealthy lifestyle amongst other things – elicits an inflammatory response which can cause calcium to deposit in the damaged tissue. This plaque buildup is the underlying mechanism that can lead you down the road to a heart attack.
However, if your intake of vitamin K2 and D is sufficient, these two nutrients will work together to increase MGP which will then inhibit calcium from being deposited in your soft tissues.
How can you predict your risk of heart disease?
One of the things you could do is to determine your calcium score test – this test measures the calcification of arteries and provides a much more accurate prediction of your future risk of heart disease than your cholesterol levels.
If your calcium score is high, taking therapeutic doses of vitamin K2 (under the supervision of your health care provider) while improving your diet and exercising more can help reduce your calcium score.
In the Rotterdam Study, scientists investigated the vitamin K2 intake of more than 4,800 men who were over 55 and thus constituted a high-risk age group for heart disease. The subjects were divided into three groups based on their vitamin K2 intake. Those with the highest intake of dietary vitamin K2 per day (33 micrograms) had a 52% lower risk of severe calcification of the aorta, a 41% reduced risk of coronary heart disease and a 51% lower risk of death due to heart disease. This group also showed a 26% lower risk of death due to any causes.
What’s really interesting is that although the study participants consumed, on average, 10 times more dietary vitamin K1 than vitamin K2, the researchers didn’t find any relationship between vitamin K1 intake and the risk markers described. In other words, simply consuming lots of vitamin K1 will not provide you with the same health benefits as dietary vitamin K2.
3. Vitamin K2 may enhance dental health.
You’re most likely aware that diet leaves a colossal footprint on teeth structure. Or that well-formed teeth are more resistant to decay.
‘How does that help me? I’m a grown up with already formed teeth…’ you’re probably muttering to yourself.
Well, let me tell you something: your teeth can heal themselves if the right nutrients and conditions are present. Although more research is warranted, current evidence suggests that vitamin K2 could help prevent and even reverse tooth decay in various ways as explained below.
Tooth decay 101
To better understand the role of vitamin K2 in teeth health, it can help to know that the tooth consists of four layers. The hardest outer shell of the tooth is known as the enamel and is the most mineralized of the four layers. Below the enamel is another protective mineralized layer, called the dentin. The pulp which contains blood vessels and nerves is found below the dentin and just above the cementum another mineralized tissue which coats the roots.
If your enamel is poorly structured – this can happen if your diet is deficient in nutrients or rich in refined carbs and sugar – it will demineralize easily. And that’s when decay sets in.
It’s worth noting that tooth decay is an opportunistic infection caused by bacteria living in the mouth. When you eat carbs (especially refined ones or sugar), the bacteria also feed on these, producing acid which gradually dissolves the enamel. As the cavity progresses, it penetrates the dentin and can reach the pulp.
Provided that your diet is healthy, decaying tooth can heal itself by:
- Remineralizing the enamel and dentin.
- Promoting the growth of new dentin – the hard-work here goes to odontoblasts, specialized cells in the pulp.
Want a healthy smile?
If so, make sure to get enough calcium, vitamin D and phosphorus in your diet – these nutrients all play a major role in the formation and maintenance of mineralization in healthy teeth and gums during childhood and adulthood.
Your teeth become more resistant to cavity formation when the protein osteocalcin triggers mineralization (the deposition of calcium and phosphorus salts in your teeth). This mineralization process strengthens the enamel while stimulating the growth of new dentin (the calcified tissue under your enamel).
Wondering what that has got to do with vitamin K2? Well, for osteocalcin to do its job effectively, it needs to be activated by vitamin K2.
Vitamin K2 may help prevent tooth decay.
Dr Weston Price reported that ‘Activator X’ (now known as vitamin K2) influenced the composition of saliva by reducing the amount of bacteria contained in the saliva. Dr Price found that a vitamin K2 concentrate could significantly reduce the Lactobacillus acidophilus count. This bacteria has been associated with tooth decay.
In an experiment, Dr Weston Price monitored the dental health of poor children after feeding them a very nutritious diet including lots of vitamin K2, vitamin D and various minerals. Before and after X-rays clearly showed that the diet helped re-calcify the children’s cavity-ridden teeth.
Autopsies have shown that the brain contains one of the highest concentration of vitamin K2 in the body – between 70 to 93% of the vitamin. This wide range in vitamin K2 concentrations in the brain may imply that we convert vitamin K1 to K2 less efficiently and are therefore more dependent on dietary vitamin K2.
Studies suggest that vitamin K2 supports enzymes that are involved in the synthesis of lipids known as sulfatides within the brain. As we age, brain concentrations of vitamin K2, sulfatides and proteins dependent on vitamin K start to fall. This decline has been linked to neurological degeneration that occurs with aging. In fact, autopsies of human brains affected with early stage Alzheimer’s disease indicate 93% lower sulfatides levels in the brain.
Neuroscientists discovered that vitamin K2 could counteract the effects of one the genetic defects which causes Parkinson’s disease, namely a reduction in mitochondrial activity. (Mitochondrias can be regarded as the power plants of cells.) When the energy producing processes of mitochondrias are disrupted, they cannot produce enough energy for the cell – this causes brain cells to start dying off, affecting communication between neurons and leading to typical Parkinson’s symptoms.
- Protein gas6 which is dependent on vitamin K2 promotes brain cell survival.
- Vitamin K2 completely protects cells that synthesize myelin against damage caused by free radicals. [The myelin is a protective fatty layer that insulate nerve fibers in the central nervous system and enables them to quickly transmit impulses from the brain to other parts of the body.]
Based on observations from animal studies, researchers speculate that a vitamin K2 deficiency could lead to fatigue and learning issues in humans. Extreme deficiencies of the vitamin can also increase predisposition to seizures.
5. Vitamin K2 can reduce recurrence of cancer.
Experiments on cells indicate that vitamin K2 possess potent anti-carcinogenic properties that may make it a potential candidate in the prevention and treatment of cancer.
Vitamin K2 is able to hamper cancer development via several pathways:
- Altering growth factors as well as the tumor’s receptor molecules– this reduces the tumor’s ability to grow and spread.
- Halting the reproductive cell cycle – this prevent the cancer cells from multiplying.
- Promoting the synthesis of a DNA-degrading protein which is usually suppressed by cancer cells. This process prevents cancer cells from effectively repairing themselves.
- Triggering programmed cancer cell death.
- Stimulating oxidative stress– cancer cells are highly vulnerable to oxidative stress. Healthy tissues remain unaffected.
- Causing cancer cells to split open – this occurs in the presence of vitamin C.
- Preventing the formation of new blood vessels which favor the rapid growth of cancer cells.
Clinical trials suggest that vitamin K2 could decrease reappearance of liver cancer and increase survival rate.
Research also shows that vitamin K2 is able to safely inhibit the development and metastasis of brain tumors, bladder cancer, colorectal cancer, human hepatocellular carcinoma (a common and lethal form of liver cancer), human leukemia cells, lung cancer, and stomach cancer.
In an observational study involving about 11,000 men, researchers found that those with the highest intake of vitamin K2 had a 63% lower risk of advanced prostate cancer. Vitamin K1 showed no such benefit.
In another study, cancer patients either received vitamin K2 or a placebo. 87% the cancer patients in the supplemented group survived the first three years compared to 64% in the control group. Plus, the group which took the supplement showed much lower cancer recurrence rates compared to the control group:
- 12.5% vs. 55.2% at 12 months;
- 39.0% vs. 83.2% at 24 months;
- 64.3% vs. 91.6% at 36 months.
Who needs extra vitamin K2?
Practically everyone – as mentioned, unlike deficiencies of vitamin K1, vitamin K2 deficiencies are very prevalent and scientists have concluded that most of us are not consuming enough of K2 to enable proteins dependent on this vitamin to function at their peak and maintain long-term health.
And if you’re diabetic, you may have a higher need for vitamin K2: patients with diabetes often have lower MGP levels in their arteries. This could be one the factors behind the higher prevalence of arterial calcification and heart disease among diabetics.
If you suffer from digestive disorders or regularly take antibiotics, you may also need more vitamin K2: if digestion is impaired, your body may not be able to absorb sufficient vitamin K2.
How can you determine your vitamin K2 levels?
Lab tests that estimate serum vitamin K2 levels are not reliable. Testing for undercarboxylated osteocalcin would be more accurate as this is an indirect marker for vitamin K2 status – this test should become more available in the future. In the meantime, try to incorporate foods rich in vitamin K2 in your daily diet.
Top 18 foods rich in vitamin K2
To keep it simple; the best sources of vitamin K2 are grass-fed animal fats and fermented foods. That’s because, unlike supplements, these foods naturally contain a panoply of nutrients that work synergistically with vitamin K2 via mechanisms not yet understood.
- Natto – 1,103.4mg/100g
- Goose Liver Paste – 369.0mg/100g
- Hard cheeses – 76.3mg/100g
- Soft cheeses – 56.5mg/100g
- Egg yolk – 32.1mg/100g
- Goose leg –31.0mg/100g
- Curd cheeses – 24.8mg/100g
- Butter – 15.0mg/100g
- Chicken Liver – 14.1mg/100g
- Chicken breast – 8.9mg/100g
- Chicken leg – 8.5mg/100g
- Ground beef – 8.1mg/100g (medium fat)
- Calf liver – 5.0mg/100g
- Sauerkraut – 4.8mg/100g
- Whole milk – 1.0mg/100g
- 2% Milk – 0.5mg/100g
- Salmon – 0.5mg/100g
- Mackerel – 0.4mg/100g
- Organ meats (especially the pancreas, reproductive organs, brains, cartilage and possibly kidneys) from grass-fed animals would also be rich in vitamin K2. Unfortunately, precise values were not available at the time this article was written.
- Vitamin K2 content of butter vary greatly between brands since the amount would depend on the quality of the pasture where the animals grew.
- Fermented foods are good sources of vitamin K2 since the anaerobic bacteria that grow during the fermentation process produce menaquinones which they can use for energy.
So how much vitamin K2 should you eat per day?
Scientists are still debating this question but the good news is that you don’t have to consume huge portions of the vitamin to experience health benefits.
In the Rotterdam Study described earlier in this article, all the participants experienced a drop in risk of heart disease; even those with the lowest vitamin K2 intake (about 21 micrograms).
In other words, simply consuming two eggs (with the yolk) per day without eating any other foods rich in vitamin K2 would allow you to benefit from vitamin K2’s numerous health properties.
Why two eggs instead of one? Well, the vitamin K2 content of the yolk depends on the diet of the animal – for instance, most egg yolks in the US would contain about 15.5mg of the vitamin per 100g compared to 32.1mg/100g in the Netherlands.
Besides consuming vitamin K2, what can you do to enhance your vitamin K2 levels?
Ensuring that your gut flora is healthy can also help you maintain healthy vitamin K2 levels in your body. That’s because the bacteria in the gut synthesize menaquinones which our bodies can absorb to some extent.
Plus a healthy gut flora will also reduce levels of inflammatory molecules in your body. It is now known that numerous chronic conditions such as heart disease, diabetes and arthritis are caused by excess inflammation in the body. Inflammation can also affect your skin by making it more prone to acne.
What about vitamin K2 supplements – are they worth the hype?
A supplement can come in handy if you don’t have access to quality grass-fed foods or fermented foods or if you need a higher dose to treat an existing health condition.
Before you buy a vitamin K2 supplement, you should know that there are two main forms of this supplement on the market, namely menaquinone-4 (MK-4), also called menatetrenone, and menaquinone-7 (MK-7).
Menaquinone-4 (MK-4) is a synthetic version of the vitamin K2 naturally present in animal fats. It is non-toxic and is thought to be identical to vitamin K2 chemically and physiologically. Most animal studies and the Japanese osteoporosis studies have utilized this form of vitamin K2.
Cost-effective MK-4 supplement options:
- Thorne Research – This is a liquid supplement which contains MK-4 dissolved in coconut oil fats and vitamin E.
- Carlson Laboratories – Less expensive than Thorne but this MK-4 comes in dry cellulose capsules that also contains fillers and thus gives you less control over the dose.
Menaquinone-7 (MK-7) is a natural fermented soy (natto) product and is much more expensive than MK4.
Cost-effective MK-7 supplement options:
- Jarrow Formulas – Contains fewer additives than Source Naturals and certifies that the soy used is not genetically modified.
- Source Naturals – Less expensive than Jarrow Formulas.
Disclaimer: Neither Bembu nor the author have received a commission for recommending the above-mentioned supplements.
Extremely important note
If you’re on warfarin, discuss with your doctor and dietitian before taking vitamin K supplements as these would affect the activity of the anticoagulant.
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