vitamin k2: everything you need to know

Lawrence Lefcort, SATI STAFF

If you’ve never heard of vitamin K2, you’re not alone. It’s been widely neglected in the Western diet and by the media at large. Other vitamins and minerals like calcium, vitamin D, and magnesium bask in the nutrient spotlight, and rightly so, but vitamin K2 is commonly overlooked.

If you’re the parent of a newborn you’ll probably remember the hospital nurse giving your baby a vitamin K shot within twenty-four hours after leaving the womb. It begs the question: if the nutrient is so important at birth, why is it we never hear mention of vitamin K ever again?

The answer is unclear, but what is certain is that according to many health professionals, if we want to keep our heart and bones healthy, we can no longer afford to ignore the value of this powerful vitamin. Below you’ll discover all you need to know about vitamin K2, its many benefits, what foods have it, and the ideal quantities in which to consume it.

The history of vitamin k: a primer

Eighty-two years ago, while investigating the effects of a cholesterol-free diet fed to chickens, Danish biochemist and physiologist Henrik Dam discovered an unknown vitamin. The chickens deprived of cholesterol began hemorrhaging and bleeding uncontrollably, and despite several attempts to solve the problem, nothing seemed able to reverse the process, not even when normal levels of fat were reintroduced.

Only when a fat-soluble compound able to stimulate blood-clotting was added to the mixture, did the chickens stop bleeding. Dam named the restorative nutrient vitamin K (representing the German word koagulation). He was awarded the Nobel Prize in Medicine in 1943 for his discovery of vitamin K and the role it played in human physiology (1).

Later research gleaned that this vital compound was necessary for effective blood clotting and could be found in two forms: K1 and K2. Vitamin K1 (phylloquinone) originates in plant foods, leafy greens, and algae while vitamin K2 (menaquinone) is created by bacteria existing in animal foods like meat, dairy, and eggs and in fermented foods such as cheese and yogurt.

In practice, vitamin K2 represents an amalgam of more specific sub-strains known as menaquinones that carry the abbreviation “MK” with the most important ones being MK-4 and MK-7.

Vitamin k1 and k2: modus operandi

Vitamins K1 and K2 interact with our bodies in different ways. They both play a crucial role in sustaining blood equilibrium and maintaining the health of our bones and heart at peak levels. Vitamin K2, in particular, helps encourage the proteins in our blood to use calcium as ideally as possible to build strong bones and restrict calcification of the arteries (2).

So what happens when these two compounds enter your system? Vitamin K1 travels directly to the liver and performs its primary function which is to produce the proteins we need for efficient blood clotting. It doesn’t tend to interact with our bones or arteries. Vitamin K2, however, heads straight to the walls of our blood vessels, bones, and tissues.

K2 operating as MK-7 reaches the bones much more efficiently than K1 and once there, produces osteocalcin, a hormone that enhances metabolism and boosts hormone vigor. Not only that, but the quantities of MK-7 that do reach the liver have longer staying power than K1 and, therefore, outperform it in blood clot functioning (3).

Our tissues absorb K2 in the form of MK-4 almost immediately after consumption, making it an excellent defender able to protect our muscles, ligaments, and tendons from calcium deposits and resist the formation of cancer cells (4). It also encourages the manufacture of sex hormones through its interaction with the sex organs. 

The bottom line is that the assortment of vitamin K2 compounds provide more impactful health benefits to the body than K1 because they hone in on the most important and significant bones and tissues. Vitamin K2 helps direct calcium to where it is supposed to be and away from where it is less useful or even harmful (5).

Vitamin k2 can boost bone health and prevent bone degeneration

If we don’t take enough calcium into our bodies, the integrity of our bone structure can weaken over time increasing the risk of bone fractures: a condition known as osteoporosis. Osteoporosis has become widespread in the United States with more than 44 million Americans over the age of 50 diagnosed with low bone mass and density (6).

Many people use calcium supplements to make up for this shortfall, and indeed the addition does encourage the development of bone mass and vitality. However, supplemental calcium comes with a cost. Research has suggested that increased intake of calcium may be linked to a surge of calcium deposits in the lining of our blood vessels, and can heighten the risk of heart disease (7). 

Enter stage left, vitamin K2: this workhorse is known to restrict the buildup of calcium in the arteries and increase the flexibility of our blood vessels (8). K2 also catalyzes the metabolism of calcium and supports the binding of the two primary proteins responsible for building and sustaining bones (9). 

The Japanese have long understood the benefits of vitamin K2 in their diets. The traditional Japanese dish called natto, which dates back to at least the 15th century, consists of fermented soybeans and is one of the richest food sources of K2 around.

One landmark clinical trial from Japan documented 944 women between the ages of twenty and seventy-nine over a three-year period. The women’s diet contained regular consumption of natto, which contains large quantities of MK-7 (10).

The researchers determined that regular consumption of natto had a positive effect on the bone mineral density of postmenopausal women and concluded that it might help prevent the progression of osteoporosis (11). Supported by the evidence of studies like these, the Japanese officially approved vitamin K2 for the treatment of osteoporosis in 1995.  

Vitamin k2 and cardiovascular health

According to the Centers for Disease Control (CDC), every year in America, more than 600,000 people die of heart disease (12), representing one out of every four deaths! It’s no surprise then, that cardiovascular disease is the leading cause of fatality for both men and women in the U.S. and worldwide, where heart-related diseases claim roughly 17.5 million lives annually (13).

But according to a plethora of observational research, vitamin K2 has demonstrated a remarkable biological ability to help prevent this tragic outcome.  Studies have shown that sufficient intake of K2 can decrease the likelihood of vascular damage by activating a protein known as MGP that limits calcium from embedding onto blood vessel walls (14).

MGP directs calcium out of our arteries and frees it up to perform what it was meant to do in our body: strengthen our teeth, bones, and fortify our skeletal structure (15). As a result, the walls of our blood vessels and arteries are liberated from the shackles of calcification leaving them feeling supple, flexible, and pumping blood like the pistons they were meant to be.

On the flip side, those who are deficient in vitamin K2 will have slower activation of MGP resulting in increased calcification in the arterial walls and causing thick plaque to form, which can lead to the development of atherosclerosis and other cardiovascular illnesses (16).

A groundbreaking study out of Holland documented roughly five thousand healthy adults over 55 and observed the link between dietary consumption of vitamin K, heart disease, and death (17). The results were significant: researchers concluded that elevated intake of vitamin K2 (about 32 mcg per day) cut the death rate from arterial calcification-related heart disease in half and reduced all-cause fatalities by 25%.

Calcium is the most abundant mineral in the body (18), but it needs to be wisely managed so that it doesn’t accumulate in our arteries, especially those that surround the heart. Vitamin K2 may have a significant contribution to make in helping to prevent calcium deposits from forming in the pathways of our blood.

K2 may play a role in preventing cancer

Cancer has placed a heavy medical and economic burden on the United States and countries around the globe. In 2016, almost 1.7 million new cancer cases were diagnosed in America, and 595,690 people died from the disease (19).

An increasing number of medical sources have begun to stress the importance of prevention as one of the primary tools to defend against the onset of the disease (20). Could vitamin K2 have a role to play in this process? Some studies say yes, observing that vitamin K2 possesses remarkable attributes in helping to prevent and even repel cancer.

A 2003 study reported in the International Journal of Oncology (21), found that intake of vitamin K2 contributed to suppressing cancerous cell growth in patients with lung cancer. The study also recommended the use of K2 as a viable alternative to more conservative cancer treatments that have been known to weaken bone marrow and stifle bone marrow development (22). The study also noted previous success stories when vitamin K2 was administered to leukemia patients.

A recent European study indicated that increased consumption of vitamin K2 might decrease the likelihood of prostate cancer by as much as 35 percent (23). Following more than 11,000 men who participated in the inquiry, researchers discovered that men who had advanced-stage prostate cancer were the greatest beneficiaries of K2 intake, showing a 63 percent decrease in risk.

Smaller, well-documented observational studies (24) have suggested a beneficial link between vitamin K2 and the battle against liver cancer and in helping patients to extend survival rates (25). Other lab studies have indicated good potential for vitamin K2 in the treatment of other types of cancer including non-Hodgkin’s lymphoma, brain tumors, colorectal, and stomach cancers (26).

The bottom line is that a sound foundation of laboratory science combined with compelling clinical evidence suggests that vitamin K2 can lend a hand in preventing and in sometimes repelling an array of common cancers. And the best news of all is that K2 is inexpensive and widely available.

Vitamin k2 helps keep your children’s teeth strong

Vitamin K2 performs a delivery service that it carries out rain or shine – it transports calcium to where it needs to go. Children need K2 to ensure that their bones, especially their facial structure, grow big and robust. Regular intake of vitamin K2 during pregnancy and in childhood can limit facial narrowing, and healthy facial bones support healthy teeth and gums.

One of the pioneers in Nutritional Dentistry and founder of the National Dental Association, Dr. Weston Price first reported on the link between vitamin K2 and dental health in the 1930s and 40s. His conclusions: vitamin K2 helps to enhance oral health, remineralize teeth, and prevent cavities (27).

Cavity-forming bacteria in the mouth erodes the outer shell of the tooth on its way to destroying the inner layers of dentin and the dental root. Dr. Price treated his patients with butter oil rich in vitamin K2 and produced from pasture-fed cows. The result: the average of his patients’ bacteria content per milliliter of saliva plummeted by 95 percent (28).

Vitamin K2 works twofold to protect our teeth: it dwindles the number of cavity-causing bacteria, and it boosts dentin with the K2-menaquinone required to activate the bone protecting proteins MGP and osteocalcin, causing calcium and other minerals to be drawn directly into the tooth tissues (29). Where a child’s oral health is concerned, a small investment in vitamin K2 may pay high dividends down the road and save you thousands in dental care costs.

Where to find all the vitamin k2 you need

It’s not hard to find vitamin K2, but you need to know where to look, as it’s found primarily in certain animal and fermented foods that some people may not usually eat. The most abundant sources of vitamin K2 are high-fat dairy products from pasture-fed cows, liver and other organs, as well as grass-fed egg yolks (30). Because vitamin K is fat-soluble, low-fat animal products are a less ideal choice.

Interestingly, meats, fats, and egg yolks from factory-bred animals contain almost no vitamin K. The reason stems from the fact that pasture-grown animals eat grass rich in vitamin K1, which they readily convert to vitamin K2. Leafy green vegetables are an excellent source of K1, but unfortunately, only our animal counterparts can transform it into vitamin K2; we humans have a much harder job of it.

You can find the two sub-compounds of vitamin K2 in different ways: MK-4 is present in milk butterfat, organs, and fats of animals, and eggs and MK-7 typically found in natto, kefir yogurt, sauerkraut, and other fermented vegetables. The foods containing the highest amount of K2 are natto, goose liver, sauerkraut, miso, and other fermented vegetables.

Cheese lovers can take heart: vitamin K2 exists in certain kinds of fermented cheese; the best choices include Gouda, Jarlsberg, Brie, and Edam. It may not be a coincidence that the Swiss, known for their high dairy and cheese diets, have the second largest longevity rate on the planet.

How much vitamin k2 should you take

Want to know for certain if you’re lacking vitamin K2? Doctors recommend undergoing two tests: a regular prothrombin time, which measures how long it takes your blood to clot; and an osteocalcin test, which will tell you the amount of uncarboxylated osteocalcin in your blood (31). High levels of uncarboxylated osteocalcin point to a vitamin K deficiency in preserving optimal bone health.

For healthy adults, nutrition doctors have recommended a daily dosage of vitamin K2 between 50 mcg and 150 mcg (32). The simplest way to get your optimal daily requirement of vitamin K2 is to eat a small bowl of natto, equal to about fifteen grams.

However, not all of us enjoy fermented soybeans let alone possess the culinary skills to make ancient Japanese dishes. For the less seasoned and adventurous among us, one solution is a high-quality K2 supplement. The benefits of supplementing K2 may be improved even more when mixed with a vitamin D supplement as the two nutrients contain synergistic effects which feed off each other (33).

Vitamin K2 is something most of us could probably use a lot more of. And foods rich in K2 are easy to find and won’t break your budget. Supplements can help compliment your K2 consumption, but shouldn’t replace a healthy, nutrient-rich diet.

The Sati line

Long ignored by Western culture, Vitamin K2 has the potential to change our lives in many ways. This soft-spoken and vital nutrient could be the answer to the widespread nutritional deficiency now seen on a global scale, and the health challenges that go with it.

Due to the growing body of clinical research into the benefits of vitamin K2, an increasing number of health practitioners are realizing the powerful implications between what we consume and the prevention of illness. It’s no longer a question of if we should consume vitamin K2 or not. The question has become how much and by what means.

Scientifically-backed evidence has demonstrated the myriad of benefits vitamin K2 bestows to our heart, blood vessels, bones, and teeth, and its contribution to preventing and even slowing the progression of certain diseases. At the end of the day, vitamin K2 is an inexpensive and widely available compound that may just be the missing nutritional link between diet and disease.