Vitamin K2 (MenaQ7)
Most people have never heard of Vitamin K2.
This vitamin is rarely found in the Western diet and hasn’t received much mainstream attention.
There are two main forms of Vitamin K… K1 (phylloquinone) is found in plant foods like leafy greens, whereas Vitamin K2 (menaquinone) is found in animal foods and fermented foods.
How do Vitamins K1 and K2 Work?
The main function of Vitamin K is modifying proteins to give them the ability to bind calcium. In this way, it “activates” the calcium-binding properties of proteins.
The roles of Vitamin K1 and K2 are quite different and many feel that they should be classified as separate nutrients altogether. Vitamin K1 is mostly used by the liver to activate calcium-binding proteins involved in blood clotting, while K2 is used to activate proteins that regulate where calcium ends up in the body (4).
Warfarin (Coumadin®) is an anticoagulant drug, a blood thinner. These drugs inhibit normal vitamin K1 & K2 functions in the body. The alarming result of vitamin K impairment is the rapid development of osteoporosis and arterial calcification.
Vitamin K1 & K2 is absolutely essential for regulating calcium balance in the body. A deficiency of vitamin K1 & K2 status causes brittle bones and a vascular system that hardens to a state of poor functionality. People who take Coumadin® suffer more osteoporotic fractures. and show substantially more abnormal calcium deposition in other areas, such as heart valves—twice as much as non- Coumadin® takers.
The fact that these pathological changes are allowed to occur in humans prescribed warfarin is unconscionable given the knowledge about the value of low-dose vitamin K supplementation, even in patients at high risk for abnormal arterial blood clots.
Vitamin K2 May Help Prevent Heart Disease
Calcium build-up around the heart is a huge risk factor for heart disease. For this reason, anything that can reduce the accumulation of calcium may help prevent heart disease.
Atherosclerosis is the leading cause of disability and death in developed societies. Many factors are involved in its initiation and progression. Homocysteine or oxidized low-density lipoprotein (LDL) can initially damage the inner arterial lining (the endothelium).29 To repair this damage, the endothelium produces collagen that forms a cap over the injury site.
These endothelial collagen caps attract calcium that accumulates (calcifies) and forms a hard material resembling bone. This is why atherosclerosis is sometimes referred to as “hardening of the arteries.”
Calcification of the coronary arteries markedly increases heart attack risk.
A substantial volume of studies shows that insufficient vitamin K2 accelerates arterial calcification. There are also studies which confirm that restoring vitamin K2 reverses arterial calcification.
In the Rotterdam study, those who had the highest intake of Vitamin K2 were 52% less likely to develop calcification of the arteries, and had a 57% lower risk of dying from heart disease, over a 7-10 year period (9).
Another study of 16,057 women found that participants with the highest intake of vitamin K2 had a much lower risk of heart disease. For every 10 micrograms of K2 they consumed per day, the risk of heart disease was reduced by 9% (10).
This is where vitamin K2 is believed to help, by helping prevent calcium from being deposited in the arteries. Vitamin K2 functions to keep calcium in the bone and prevent its buildup in the arteries. However, newly published research indicates vitamin K2 possesses a host of additional benefits.
Vitamin K2 May Help Improve Bone Health and Lower The Risk of Osteoporosis
Osteoporosis (“porous” bones) is a common problem in western countries.
It is especially common among women and strongly raises the risk of fractures, starting around the age of 40. As mentioned earlier, Vitamin K2 plays a central role in calcium metabolism, the main mineral found in bones. Vitamin K2 activates the calcium-binding activity of two proteins called Matrix GLA protein and osteocalcin, which help to build and maintain bones.
Bone is living tissue that is in a constant state of renewal. The maintenance of bone first requires old bone to be dissolved by cells called “osteoclasts.” When the activity of osteoclasts is too high, large holes develop that weaken the bone and lead to osteoporosis. Vitamin K2 is the key to turning off excess osteoclast activity and bone degradation.
The holes left by osteoclasts are prepared for remodeling by osteoblast cells. The osteoblasts secrete a protein called osteocalcin, which enables new calcium to be laid into the bone. The calcium-binding properties of osteocalcin require vitamin K2, whereas the synthesis of osteocalcin itself requires vitamin D3.
Vitamin K2 provides two critical benefits to the bone. First, it protects against excess bone degradation (resorption) by turning off excess osteoclast activity. It then supports new bone formation by enabling osteocalcin to pull calcium from the blood and layer it on to the bone.
From this brief description, it is clear that maintenance of healthy bone density requires adequate levels of calcium, vitamin D3, and vitamin K2. Without vitamin D3, there will be no osteocalcin for vitamin K2 to work on. Without vitamin K2, the osteocalcin that is produced will be inactive. Of course, without calcium there will be no minerals for the activated osteocalcin to attract to the bone for structural density.
Interestingly, there is also quite a bit of evidence from controlled trials that K2 has major benefits for bone health.
A 3-year trial in 244 postmenopausal women found that those taking vitamin K2 supplements had much slower decreases in age-related bone mineral density (15).
Seven additional trials found that vitamin K2 reduced spinal fractures by 60%, hip fractures by 77% and all non-spinal fractures by 81% (16).
In line with these findings, the Japanese govenrmnet reccommends vitamin K supplementation for the prevention and treatment of osteoporosis. (17)
Vitamin K2 has proven to be as effective as prescription drugs in reducing the incidence of bone fractures. A Japanese study in postmenopausal women compared the effect of K2 (MK-4) with the drug etidronate (Didronel®) on the incidence of vertebral (spine) fracture. Women taking K2 at a dose of 45 mg per day experienced a fracture rate of 8.0% compared with 8.7% for those taking etidronate drug therapy. Furthermore, women taking both MK-4 and the drug experienced only a 3.8% fracture rate. In a placebo group that received neither K2 nor drug therapy, nearly 21% of women experienced bone fractures.69
Vitamin K2 Improves Dental Health
Research shows that Vitamin K2 may affect dental health.
However, no human studies have tested this directly.
Based on animal studies and the role vitamin K2 has in bone metabolism, it is reasonable to assume that it impacts dental health too.
One of the main regulating proteins in dental health is osteocalcin, the same protein that is critical to bone metabolism and is activated by vitamin K2.
Osteocalcin triggers a mechanism that stimulates growth of new dentin, which is the calcified tissue underneath the enamel on your teeth.
Vitamin A and D3 are also believed to play an important role here, working synergistically with vitamin K2 to enhance osteocalcin.
Vitamin K2 Helps Fight Cancer
Cancer is a common cause of death in Western countries.
Even though modern medicine has found many ways to treat cancer, new cancer cases are still on the rise.
Therefore, finding effective prevention strategies is of utmost importance.
K2 to the rescue
Vitamin K2 induces differentiation and apoptosis (cell destruction) in a wide array of human cancer cell lines. A search of PubMed reveals a number published studies that confirm the role of vitamin K2 in the treatment of cancer.1-15
One goal of independent cancer researchers is to identify compounds that cause cancer cells to self-destruct. Vitamin K2 has been shown to induce apoptosis (cell destruction) in leukemia cells. A study published in July 2008 identified yet another pathway by which vitamin K2 causes the degradation (via autophagy) of leukemia cells’ own components. The scientists noted that apoptosis and autophagy in leukemia cells can be simultaneously induced by vitamin K2. Vitamin K2 produces inhibitory effects against myeloma and lymphoma, confirming the benefits of application for individuals fighting these all too common cancers.
Infection with the hepatitis B or C virus is a major risk factor in developing primary liver cancer, known medically as hepatocellular carcinoma. It can also occur in those who do not have hepatitis. A study published in the Journal of the American Medical Association showed that in those with viral-induced liver cirrhosis, less than 10% of patients given vitamin K2 developed liver cancer. In similar patients not given vitamin K2, a startling 47% developed primary liver cancer.41 Vitamin K2 decreased the risk of hepatocellular carcinoma.
In 2007, scientists identified specific anticancer mechanisms for vitamin K2, including inhibition of proinflammatory nuclear factor-kappa B (NFkB) that is often over-expressed in cancer cells. 43 Tumor cells use proinflammatory factors to develop survival mechanisms that thwart conventional attempts to eradicate them.
Interestingly, several studies have been done on Vitamin K2 and certain types of cancer.
Two clinical trials suggested that vitamin K2 reduces recurrence of liver cancer and increases survival times (24, 25).
An observational study on 11,000 men also found that a high vitamin K2 intake was linked to a 63% lower risk of advanced prostate cancer. Vitamin K1 had no effect (26).
Why K2 (MenaQ7)?
There are two forms of vitamin K2 that have demonstrated remarkable benefits in published scientific studies.
The MenaQ-4 form of vitamin K2 is the most rapidly absorbed and has many of the proven clinical benefits, of MenaQ-7. Yet MenaQ-4 remains active in human blood for only a few hours after ingestion.
The MenaQ-7 form of vitamin K2, the one used in COR-Restor, on the other hand, remains bioavailable in the human body many days after ingestion.
In a human clinical trial, comparisons of bioavailability after ingestion of vitamins K1 and K2 (MK-7 form) were performed. The results showed that over a 24-hour period, MK-7 was present in the blood 2.5-fold better than K1. Over a 96-hour period, MK-7 was six-fold better than K1.57 (Shown to the right on Figure 1.)
A dose-response study was done where healthy volunteers received increasing doses of K1 and K2 (MK-7). The results showed no effect of K1 observed 24 hours after a 200 microgram dose, whereas 100 micrograms of K2 provided optimal vitamin K blood levels over a 24-hour period. 57 (Shown to the right on Figure 2.)
A third clinical study compared K1 with K2 (MK-7 form) at the same dose over a six-week period. Compared with K1, the level of MK-7 form of vitamin K2 was seven- to eight-fold higher in the blood and there was no cumulative effect of K1 This suggests that MK-7 is more efficacious than K1.57 (Shown to the right on Figure 3.)
Humans can partly convert vitamin K1 to K2 in the body. This is useful because the amount of vitamin K1 in a typical diet is ten times that of vitamin K2.
However, current evidence indicates that the conversion process is inefficient, because we benefit much more from eating vitamin K2 directly.
Vitamin K2 is also produced by gut bacteria in the large intestine, and there is some evidence that broad-spectrum antibiotics can contribute to K2 deficiency (27, 28).
Unfortunately, the average intake of this important nutrient is incredibly low in the modern diet.
Vitamin K2 is mainly found in certain animal foods and fermented foods, which most people don’t eat much of.
Animal sources include high-fat dairy products from grass-fed cows, liver and other organs, as well as egg yolks (29), although the level of Vitamin K2 in these sources are very low.
Vitamin K is fat-soluble, which means low-fat and lean animal products don’t contain much of it.
Animal foods contain the MK-4 subtype, while fermented foods like sauerkraut, natto and miso contain more of the longer subtypes, MK-5 to MK-14 (30).
If those foods are inaccessible to you, then supplementation is a valid alternative.
The benefits of supplementing K2 is upon having vitamin D3 present, because the two vitamins have synergistic effects (31).
Bottom Line: The main function of Vitamin K is to activate the calcium-binding properties of proteins. K1 is mostly involved in blood clotting, while K2 helps regulate where calcium ends up in the body. Thus, K2 used in CM, can be taken safely by individuals who are on blood thinners. I’ll caution you that most physicians will not be aware of this information.
Bottom Line: Vitamin K2 plays an essential role in bone metabolism and studies suggest that it can help prevent osteoporosis and fractures.
Bottom Line: It is believed that Vitamin K2 may play a critical role in dental health, but there are currently no human studies to support this.
Bottom Line: Vitamin K2 has been found to improve survival in patients with liver cancer. Men who consume the most K2 have a lower risk of advanced prostate cancer.