If there is one book that I wish every physician (and lay person for that matter) would pick up and read it is: Vitamin K2 and the Calcium Paradox: How a Little Known Vitamin Could Save Your Life by Kate Rheaume-Bleue, ND. The pharmaceutical companies certainly wish copies of this critically important book wouldn’t get around. With news as good as this, the top killer in this country--heart disease and specifically coronary artery disease--might plummet to levels so low our cardiologists would have a lot more free time on their hands. And the sales of certain medications, including statins and Fosamax, might also soar downwards. We might start to question even more deeply our antagonistic relationship with cholesterol--an essential steroidal molecule in the body vital for stable reproductive hormone levels that are critical for bone health, and--yes--arterial health as we age.
Speaking of time, if it’s a commodity you don’t currently have, I’m going to save you the trouble of even buying and reading this book. If you read this article today and follow the practical advice Dr Rheaume-Bleue recommends, you might just save yourself or your loved ones from future stroke or heart attack, osteoporosis and bone fractures with aging.
Do you know when the first electrocardiograph (ECG) machine was brought to the United States from Germany by Alfred Cohn in 1909 they laughed at him? Heart disease was so rare back then, they didn’t think they would find much use for it. Few people alive today are old enough to remember the epidemic of coronary heart disease that began in the 1920’s and 1930’s. Previously an uncommon disease, by the 1950’s coronary artery disease (CAD) or coronary heart disease (CHD) had become the leading cause of death.
If you think this is because our ability to detect coronary artery disease through means such as the ECG radically improved during this time, think again. The following article debunks this theory, citing two important studies that outline a dramatic increase in incidence of deaths due to myocardial infarction (MI) and coronary thrombosis (arterial blockage in the heart) beginning in the 1920’s. One study by Dr Robert Finlayson, published in 1985 in the journal Medical History, systemically scrutinized autopsy reports from St. Bartholemew’s Hospital in London, which had conducted routine and detailed cardiac autopsies since 1868. This study shows rates of death due to ischemic heart disease at less than 1% of the population in 1880, remaining fairly level at about 5% until about 1920, with a steady and dramatic incline after that to between 30 and 35% of the population in 1982. In other words, heart attacks are largely an occurrence of the last 80 years.
What happened in the 1920’s and 1930’s that would have so profoundly affected heart disease? Here is one theory: the introduction of large scale industrialized farming methods. Cattle and livestock that had previously grazed on wild pasture on small farms, were suddenly transferred to large grain-fed feedlots. Chickens happily clucking around a farmyard eating worms and weeds were transferred to factories, where they were fed grains, corn and soy. What is the problem with this? One problem, as it turns out, was the sudden absence of an essential vitamin we now call vitamin K2 in our diet.
So what is vitamin K2? Is it similar to, or different from, vitamin K1 we have been so much more familiar with the past fifty years? And if it is so essential, how come it took medical researchers until 2007 to finally pinpoint its critical role in the distribution of calcium in bone and body tissue? Finally, what are the best sources of vitamin K2?
What is vitamin K2? What is its identified function in the body?
Here is a direct quote from Vitamin K2 and the Calcium Paradox: “Vitamin K2 works by activating a number of special proteins that move calcium around the body. Specifically, K2 activates a protein called osteocalcin (OC), which attracts calcium into bones and teeth, where calcium is needed. K2 activates another protein called matrix gla protein (MGP), which sweeps calcium out of soft tissues like arteries and veins, where the mineral is unwanted and harmful. When K2 is lacking, the proteins that depend upon K2 remain inactive. The Calcium Paradox then rears its ugly head with an insidious decline in bone mineral density and an even more treacherous hardening of the arteries. When K2 is plentiful, bones remain strong and arteries remain clear.”
In a nutshell, enzymes (largely comprised of certain DNA-coded proteins) are the main catalysts by which the body performs vital biochemical reactions. When it comes to calcium placement, the protein enzymes mentioned above, OC and MGP, are the two “vehicles” by which the body ensures that calcium is placed where is belongs: in the bones and teeth, and not in the arteries. In other words, calcium binds with OC to get placed into bones and teeth, and it binds with MGP to be carried out of the body tissues. Here is what you need to understand: when K2 levels are inadequate, OC and MGP are useless, essentially wandering about aimlessly, unable to prevent calcium from embedding in soft tissues and unable to allow it to enter into bone. These proteins are activated exclusively and ONLY by vitamin K2, which serves to “switch on” or “unlock” their ability to then bind with calcium and perform their vital roles.
Is vitamin K2 similar or different from vitamin K1?
To clear up another misunderstanding: vitamin K2 is NOT vitamin K1. Vitamin K1--also called phylloquinone--is found in the green tissues of plants, playing a vital role in the plant’s ability to convert the energy from photosynthesis into glucose. When animals consume vitamin K1, part of it goes into the liver where it serves to activate blood clotting proteins. But part of K1 is converted to K2--also called menaquinone-- in the tissues of the animal, serving a host of physiological purposes, including the placement of calcium, that we are only now uncovering.
In fact, the richness of the green color of grass and its rate of growth both determine the concentration of K1. Animals consuming greener, more rapidly growing grass will accumulate greater vitamin K2 in their tissues in proportion to the amount of K1 in their diet. The beta-carotene associated with K1 will impart a yellow or orange coloring to the animal products--making milk, cheese and butter a deeper yellow, or egg yolks a rich dark orange. The color of these foods then, are a good indicator of the presence of vitamin K1 in their diet.
In light of this, an easy assumption to make is that if we consume enough green vegetable matter then we will convert what we need into vitamin K2. Unfortunately, there is no clear evidence at the moment that humans have the same ability to convert K1 to K2. The ability to convert K1 to K2 appears to vary widely between species and breeds of animals. German researchers who first discovered this conversion, for example, found that rats made it poorly compared to birds.
Epidemiology and intervention studies all show that intake of vitamin K2 has a superior impact on optimal human health over K1. Intake of K2 is inversely associated with heart disease in humans (see Rotterdam Study here), while intake of K1 is not. Vitamin K2 appears to be at least three times more effective than vitamin K1 at activating proteins related to skeletal metabolism. Finally, primitive groups studied went to great lengths to procure foods rich in vitamin K2 like organs and fats of animals, as well as deeply colored orange butter from animals grazing on rich pastures--a testimony to their innate understanding of the importance of these foods for health.
If it is so essential, how come it took medical researchers until 2007 to finally pinpoint K2’s critical role in the distribution of calcium in bone and body tissue?
Although both K vitamins were discovered and characterized in the 1930s, two fundamental misunderstandings about these vitamins persisted for over sixty years: the medical and nutritional communities considered blood clotting to be their only role in the body, and considered vitamins K1 and K2 to simply be different forms of the same vitamin. We now know that this is not the case. The first vitamin K-dependent protein relating to skeletal metabolism was not discovered until 1978. But it was not until 1997, nearly twenty years later, that the recognition that vitamin K was “not just for clotting anymore” broke out of the confines of the fundamental vitamin K research community.
What are the best sources of vitamin K2? Do I need to supplement?
All foods high in K2, with the exception of a Japanese fermented bean dish called natto that I will explain in a minute, come from animal or animal sources. The highest amounts are found in hard and soft cheeses from pasture raised cattle, liver and other organ meats (goose liver being especially high), egg yolks from pasture-raised chickens or other poultry, and smaller amounts in pasture-raised meat.
As I mentioned previously in this article, the amount of K2 that will be available in the animal tissue or animal product will depend on the amount of K1 present in the plants that they are consuming. Grain, soy and corn fed meat and poultry and their dairy/egg products are all but devoid of K2. Wild, or pasture-raised meats, organs, dairy, and eggs will contain K2. The deeper yellow or orange-colored the dairy or eggs, the higher the amount of K2. Animals feeding on rapidly growing, rich-colored green grass (i.e. in the spring and sometimes the fall) will tend to have higher amounts.
By the way, years ago when I lived out in Western Nebraska, I used to purchase farm eggs from a lady who let her chickens run wild on her property. I have never seen egg yolks before or since as dark as these--they were colored a deep dark orange. When I started learning about K2, I conducted a little experiment, and bought pasture-raised eggs from all the different brands that I could find at my local health food stores. I found the deepest colored eggs were from Vital Farms, although they are still several shades lighter than the Nebraska eggs.
Now, if you are a hard-core vegan--don’t despair! The “superstar” of K2--with literally four times the K2 of its nearest animal source (goose liver)--is a Japanese fermented breakfast bean dish called “natto”. It turns out that K2 is also produced by certain classes of bacteria (and explains why hard and soft cheeses top the list of K2-rich animal sources). Natto is produced by the K2-mega-producing microbe Bacillus subtilis, and the result is this product brimming with menaquinone. Interestingly enough, natto is frequently eaten in the eastern regions of Japan, but not so much the western regions. As it turns out, studies show that hip fracture rates are significantly lower in areas where it is consumed.
Apparently this slimy bean dish is a bit of an acquired taste. Nevertheless, if you are up for the challenge, I say “Go for it!”. If not, thankfully, there is a supplement now available that contains the form of K2 found in natto--specifically menaquinone-7 or MK-7.
With regard to supplementation, the form of menaquinone or K2 found in animal sources is menaquinone-4 or MK-4, and I have noticed many K2 supplements these days will contain some combination of MK-4 and MK-7. Apparently, the half life of MK-4 (or how quickly it decreases its concentration in body tissues by half) is only two or three hours, much shorter than that of MK-7, requiring it to be consumed as a supplement several times a day for therapeutic benefit. In addition the MK-4 used in supplements is not obtained from natural animal sources, but from the extract of common tobacco. MK-7 supplements, however, are sourced from natto, only require a single daily dose due to a longer half life, and provide all the same benefits as MK-4.
As far as how much to take, there is still more research that needs to be done. Researchers see a reduction in arterial calcification and cardiovascular mortality with as little as 45 mcg/day, whereas frequent natto eaters may be getting more than 300 mcg/day. So far vitamin K2 has no known toxicity and will depend on your intake of vitamin A and D (see below). Daily recommendations by Dr Rheaume-Bleue include 120 mcg/day, but she also states that it’s easily safe to double the dose. Menopausal and postmenopausal women--as well as adolescents--have a higher need for K2 and can take 240 mcg/day or more.
Final note on the synergistic relationship between vitamins D, A, and K2:
One of the most fascinating aspects of uncovering this essential “new” vitamin, is its highly synergistic relationship with both vitamins A and D.
Remember the protein matrix gla protein (MGP), that when activated by K2 carries calcium out of the soft tissues and arteries of the body? Vitamin D is essential in the production of the MGP protein. Thus, the more vitamin D, the more the production of MGP proteins goes up. That’s great if you want more MGP proteins to direct calcium away from the arteries and into the bones...but not so great if there is inadequate amounts of K2 in the system to activate them. Thus, the more vitamin D you either absorb through the sun or take as a supplement, the greater the need for K2. Together, these two vitamins can create strong bones and teeth, and clear arteries.
What about vitamin A? By the way, when we mention vitamin A here, we are referring to animal-sourced retinyl palmitate, not to plant-based beta-carotene, which is a potential precursor to vitamin A but is not necessarily converted at amounts required for optimal health. By far the best source of vitamin A actually comes from liver, one of the most prized foods among traditional peoples of the world, and often “baby’s first food” in these cultures.
Both vitamins A and D are essential in the production of osteocalcin (OC) proteins that direct calcium into bones and teeth. By itself however, vitamin A actually limits the production of MGP proteins. This may sound detrimental to heart health (and in large amounts on its own it would be), but working in tandem with vitamin D and K2, it effectively limits or spares the body’s requirements for K2, allowing the body to get by on less. In other words, when K2 is scarce, vitamin A does damage control.
The realization here, is that all three fat-soluble vitamins work together, and are needed for optimal heart and bone health.
There are more benefits of vitamin K2 that are being discovered--including its role in dental health and the formation in childhood of a wide enough dental arch so that tooth-crowding doesn’t occur, as well as its protective effect against dental cavities. Interestingly enough, breast milk is very high in K2 (when it is available to the mother). The brain contains one of the highest concentrations of K2 in the body, as do the pancreas and salivary glands. Studies are ongoing in identifying the specific role of K2 in neurological health, particularly as we age, and there has been a connection made between levels of K2, activated osteocalcin (OC) and diabetes.
The point of sharing all of this with you? Do yourself a favor and make sure this critical nutrient is either a mainstay of your diet, and/or added as a supplement into your daily regimen.
Main Sources:
Vitamin K2 and the Calcium Paradox, by Kate Rheaume-Bleue, B.Sc., N.D.
"On the Trail of the Elusive X Factor: A Sixty-Two-Year-Old Mystery Finally Solved", by Christopher MasterJohn, February 8, 2008, westonaprice.org
"The Coronary Artery Disease Epidemic", by Stephan Guyenet, May 12, 2009, wholehealthsource.blogspot.com