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LE Magazine January 2009
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Protection Against Arterial Calcification, Bone Loss, Cancer, and Aging!

By William Faloon

Can Vitamin K be Used in Those Taking Coumadin®?

Can Vitamin K be Used in Those Taking Coumadin®?

Patients prescribed anticoagulant drugs like warfarin (Coumadin®) are often advised to avoid consuming foods that contain vitamin K. The theory behind this is that dietary vitamin K can circumvent the anticoagulant properties of the drug. The horrific downside to this vitamin K deficit is arterial and valvular calcification along with weakened bones, as previously described.

Life Extension has suggested that patients taking anticoagulant drugs like warfarin ask their doctors if they can take a moderate dose of vitamin K2 to not only provide the body with this vital nutrient, but to also better stabilize the anticoagulant effects of the drug.

Published studies indicate that when warfarin-treated patients take consistent amounts of vitamin K, blood indicators of coagulation (such as the international normalized ratio or INR) become more stable, which is of critical importance. The reason that consistency is so important is that an INR reading too low places the patient at risk for developing a blood clot inside an artery or vein, whereas an INR ratio that is too high predisposes the patient to abnormal bleeding (internal and external).

Maintaining the INR within a narrow therapeutic range is a challenge for many doctors. In fact, when a patient’s INR level gets too high, the antidote is an injection of vitamin K to quickly bring it down to a safe range.

How Vitamin K Protects Our Arteries

The action of vitamin K in the body is to carboxylate proteins. Carboxylation can be defined as adding a carboxyl group into a compound or molecule. When a protein is carboxylated, it undergoes a chemical conversion that changes its function.

Vitamin K maintains normal coagulation, preserves bone, and protects against calcification by carboxylating specific proteins in the body.61

In the arteries, vitamin K is required to carboxylate matrix Gla-protein. If matrix Gla-protein is under-carboxylated, then it is unable to perform its normal function in protecting arteries against excess accumulation of calcium, or inhibiting vascular calcification.

Matrix Gla-protein is a calcification inhibitor that requires sufficient vitamin K to function optimally. The effect of vitamin K in carboxylating matrix Gla-protein is how it protects against arterial calcification.50

In a recent study in healthy individuals, Coumadin® was administered to elevate INR to 2.0, which is double the normal value for healthy adults. A higher INR means the blood is less able to clot. At a dose of 95 micrograms of MK-7, the INR dropped from 2.0 to 1.7.56

Based on what we now know about vitamin K and warfarin, a doctor might consider increasing the amount of warfarin to bring the INR back into the desired range, while enabling the patient’s vascular and skeletal systems to benefit from vitamin K.

If you are taking anticoagulant drugs, do not initiate vitamin K without your doctor’s approval. It is important for your INR levels to be carefully monitored during the first two months of combining moderate-dose vitamin K with warfarin.

Please know that enlightened doctors are increasingly expressing concern about the adverse effects of long-term vitamin K deficits in warfarin-treated patients.


Reduction in All-Cause Mortality 26%

Reduction in Coronary Artery Disease 57%

Reduction in Severe Aortic Calcification 52%

Do Healthy People Have to Worry About Taking Too Much Vitamin K?

While vitamin K is required for healthy blood clotting, taking too much does not increase the risk of an abnormal clot. The reason is that vitamin K causes a complete chemical conversion (carboxylation) of coagulation-dependent proteins in the body to put them into an active form.

Once these coagulation proteins are acted upon by vitamin K, they are 100% carboxylated. If you take additional vitamin K, nothing will happen because all of the coagulation proteins that can be carboxylated are already carboxylated. It is not possible to over-carboxylate coagulation proteins because they are already 100% carboxylated by the vitamin K you took.

Patients predisposed to abnormal blood clots, such as those with mechanical heart valves, atrial fibrillation, or prothrombotic factors in the blood are prescribed drugs like warfarin that interfere with the carboxylation of coagulation proteins. It is only in patients taking these anticoagulant drugs that the dose of vitamin K and the drugs need to be closely measured to achieve the optimal therapeutic INR range (usually around 2.5 in people who take warfarin).

To demonstrate the safety of vitamin K2, people living in the Japanese regions where natto is regularly eaten have several-fold greater blood levels of vitamin K2 (MK-7).36 The effect of high amounts of vitamin K in the blood is less osteoporosis, fewer bone fractures, and fewer heart attacks.23,30,36,46,63-65

Vitamin K and Aging

As we age, calcium deposits tend to accumulate in soft tissues throughout our bodies.

Vitamin K and Aging

Doctors performing autopsies on elderly people used to comment that it appeared that the soft tissues in these once supple bodies had turned to stone. These doctors were referring to the systemic calcification occurring virtually everywhere except the skeleton.

Systemic calcification means that calcium that is supposed to be deposited in the bones is instead being lodged in soft tissues where it does not belong. Many age-related diseases can be linked to calcification including kidney stones, arthritis, cataracts, heart valve insufficiency, bone fractures, wrinkled skin, bone spurs, senility and, of course, coronary atherosclerosis. Restoring optimal vitamin K status may help to protect against all of these disorders.

Osteoporosis is a classic age-related disease. A systemic review of 13 randomized controlled human trials that gave adults either vitamin K1 or K2 supplements for at least six months found that except for one, supplemental vitamin K1 or K2 reduced bone mass loss. Vitamin K2 in particular was associated with increased bone mineral density.66

In all trials to evaluate fracture risk, vitamin K2 was most effective. It reduced the risk of vertebral fractures by 60%, hip fractures by 77%, and all non-vertebral fractures by an astounding 81%.66

As can be seen on the chart on this page, higher ingestion of vitamin K results in a 26% reduction in all-cause mortality.46

Based on the enormity of published scientific studies, maintaining optimal vitamin K status would appear to be an essential component of a comprehensive anti-aging program.

Which Form and What Dose of Vitamin K is Optimal?

There are scientific studies that document the benefits of vitamin K1, vitamin K2 (in the MK-4 form), and vitamin K2 (in the MK-7 form).

Based on a careful evaluation of the various forms of vitamin K, and the wide range of dosage safety and efficacy data that have been established, it would appear ideal for health-conscious individuals to consume all three of these vitamin K forms.

The significantly longer-acting MK-7 makes this form of vitamin K2 essential, whereas an abundance of animal and human data confirms significant health benefits of the MK-4 form of vitamin K2, as well as vitamin K1.

Which Form and What Dose of Vitamin K is Optimal?

Fortunately, all these forms of vitamin K are relatively low-cost and can readily fit into most consumers’ supplement budget.

According to the US Department of Agriculture, it used to appear that Americans consumed many times the recommended daily requirement for vitamin K in their diets. But improved analytical methods show that vitamin K is not as abundant in the diet as once thought.

The RDA for vitamin K1 and K2 combined is 65 micrograms per day for adult females and 80 micrograms per day for adult males. While these amounts may be enough to enable blood to properly clot, they fall way below the levels found in published studies needed to protect against age-related diseases.

One reason for the confusion over optimal vitamin K intake is that only a small amount is needed for blood to properly clot, whereas much higher levels are needed to protect against osteoporosis and calcification of soft tissues (including arteries).

Consuming 100 micrograms of the MK-7 form of vitamin K2 may in itself provide optimal systemic vitamin K saturation, yet one cannot ignore the documented benefits of consuming higher amounts of vitamin K1 and the MK-4 form of vitamin K2.

With the availability of cost-effective MK-7, the total vitamin K potencies needed to be ingested can be drastically reduced. Remember that compared with other forms of vitamin K, the MK-7 form of vitamin K2 remains in the bloodstream longer and reaches levels seven- to eight-fold higher.57

This means that just 100 micrograms of MK-7 can provide greater benefits than far higher potencies of other forms of vitamin K1 and K2.


Vitamin K was discovered in 1929 and it was initially thought to only be required for healthy blood clotting. Over the past 10 years, a large body of research has focused on new areas of vitamin K metabolism, which include its critical effects on bone and vascular health; cell growth, regulation, migration, proliferation, and apoptosis; immune support; and suppression of chronic inflammatory factors.

Most conventional doctors wallow in an egregious state of ignorance regarding vitamin K and have no idea of its critical importance to their aging patients.

Fortunately, people not taking anticoagulant drugs can safely take doses of vitamin K that exceed the miniscule levels the government says we need.

New forms of vitamin K enable health-conscious individuals to take this nutrient just once a day and enjoy sustained 24-hour benefits.

When Life Extension introduced its members to vitamin K almost a decade ago, it was difficult to know that it would prove to be as effective as recent studies have demonstrated.

It is gratifying to know that most Life Extension members have obtained the broad-spectrum protection of this too often overlooked nutrient. On the flipside, there appears to be an epidemic of age-related disorders in the general population related to less than optimal intake of vitamin K.

If you have any questions on the scientific content of this article, please call a Life Extension Health Advisor at 1-800-226-2370.


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