Vitamin K1/K2

Vitamin K is found in foods such as green leafy vegetables, soy products, egg yolks and cauliflower. The average daily consumption is 100mcg (0.1mg) or less. All forms of vitamin K should be taken with fat/oil, as it is an oil-soluble (also called fat-soluble) vitamin. 5-15mg of K1 is a common recommendation among holistic doctors.

While K1 is preferentially used by the liver to activate blood clotting proteins, K2 is preferentially used by other tissues to deposit calcium in appropriate locations, such as in the bones and teeth, and prevent it from depositing in locations where it does not belong, such as the soft tissues.

Vitamin K3 is one of the many man-made versions of vitamin K. It is also called menadione. It is converted into the active form of K2 inside of the body. K3 is less utilized medically than it was in former times, due to toxicity concerns.

Unusually large doses of any vitamin K should be avoided if one is also taking an anticoagulant drug. Coumadin (Warfarin Sodium) is used to lower the chance of blood clots forming. Your liver makes clotting factors that help the blood clot and prevent bleeding. Some blood clots can cause serious medical problems. Coumadin blocks the formation of clotting factors in the liver that are dependent on Vitamin K.

Vitamin K can interfere with the blood-thinning effects of Coumadin, so it is important to maintain a consistent amount of Vitamin K in your diet. Avoid drastic changes in your dietary habits. For instance, eating large amounts of green leafy vegetables, natto or supplementing extra vitamin K, when you normally do not, can increase the amount of Vitamin K in your system.

Although animals can convert vitamin K1 to vitamin K2, a significant amount of evidence suggests that humans require preformed K2 in the diet to obtain and maintain optimal health.

It is therefore important to distinguish between K1 and K2. Vitamin K1 (phylloquinone) enters the diet from the consumption of plants. Vitamin K2 (menaquinone) is made by bacteria that line the gastrointestinal tract. However, most of the vitamin K2 produced in the intestine is embedded within bacterial membranes and not available for absorption. Thus, intestinal production of K2 likely makes only a small contribution to vitamin K status. Vitamin K2 is also made by bacteria, such as Bacillus subtilis, in the process of making natto. Significant amounts of vitamin K2 are produced during the fermentation process, making natto the best natural source of K2. It can also be found in both hard and soft cheese, and in lesser amounts in egg yolk, butter, chicken liver, salami, chicken breast, and ground beef.

Many people are not aware of the health benefits of vitamin K2. The K vitamins have been underrated and misunderstood until late in the 2000-2010 decade in both the scientific community and the general public. K2 has many benefits that K1 does not have, including:

  • reducing the risk of prostate cancer
  • improving bone loss seen in osteoporosis
  • reducing the risk of heart disease
  • maintaining skin health
  • maintaining brain function

The most effective forms of K2 are MK4 and MK7. The much longer half-life in the body of MK7 make it the form of choice.

The best sources of K2 are natto, cheese and cheese curd:

-15gms (1/2 ounces) of natto contains roughly 200mcg of K2.

-100gms (3 1/2 ounces) of cheese contains roughly 45mcg of K2.


Vitamin K1/K2 can help with the following


Bruising Susceptibility

Low levels of vitamin K are sometimes suspected as a contributing factor to bruising. Vitamin K is found in foods such as green leafy vegetables, soyfoods, egg yolks and cauliflower.


IBS (Irritable Bowel Syndrome)

See the link between IBS and Vitamin B12.


Chronic Inflammation

[Int J Vitam Nutr Res. 1997;67(5): pp.350-6]


Anticoagulant Use

Significantly increasiing your vitamin K intake while on anticoagulant therapy can reduce the desired effect. Only change you vitamin K intake with your doctor’s approval.


Metabolic Syndrome (Syndrome X)

In a published study of 38,094 Dutch men and women ages 20 – 70 it was found that vitamin K2 intake had a statistically significant inverse relationship to the risk of developing type 2 diabetes. Vitamin K1 intake also trended in the preventive direction, though the benefit was not enough to be statistically significant. This finding corresponds to the science showing that vitamin K2 is a more potent activator of osteocalcin than vitamin K1 (although both help).



Osteoporosis / Risk

In a 3 year study of postmenopausal women, vitamin D, minerals and vitamin K were used to determine vitamin K’s effect on bone loss. The use of vitamin K, along with other nutrients, reduced femoral neck bone loss, but not lumbar spine bone loss when compared to a similar supplement list without vitamin K. [Calcif Tissue Int 2003;73(1): pp.21-6]

Numerous studies published in 2008 have shown that vitamin K not only helps regulate calcium balance in the body to ensure calcium remains in the bones and away from heart valves and arteries, but it has demonstrated numerous other health benefits. In addition, scientists have been able to develop a form of the nutrient that stays in the body longer than previous forms and is more cost effective to purchase.

Maintaining consistent levels of calcium is essential, especially as we age. Studies have shown that a vitamin K2 deficiency can lead to brittle bones and hardening of the arteries. Conversely, a new study shows that restoring the nutrient can actually reverse the normal aging process of arterial calcification. Another study published in 2008 demonstrated that postmenopausal women in Japan who took both Fosamax and vitamin K2 for one year had a greater increase in neck bone density than women who only took Fosamax. And an in vitro study published in January 2008 led doctors to conclude that taking a combination of vitamins D3 and K1 can offer a “low-cost strategy for laying down new bone material.”

“Clinically, vitamin K2 sustains the lumbar bone mineral density (BMD) and prevents osteoporotic fractures in patients with age-related osteoporosis, prevents vertebral fractures in patients with glucocorticoid-induced osteoporosis, increases the metacarpal BMD in the paralytic upper extremities of patients with cerebrovascular disease, and sustains the lumbar BMD in patients with liver-dysfunction-induced osteoporosis. Vitamin K deficiency, as indicated by an increased circulating level of undercarboxylated osteocalcin, may contribute to osteoporotic fractures. Even though the effect of vitamin K2 on the BMD is quite modest, this vitamin may have the potential to regulate bone metabolism and play a role in reducing the risk of osteoporotic fractures.” [Iwamoto J, Takeda T, Sato Y. Curr Pharm Des 2004; 10:pp. 2557-2576.]

So for osteoporosis prevention and treatment, vitamin D, vitamin K2, and calcium, used in combination should result in the desired effect.


Organ Health  

Increased Risk of Diabetes ll

In a published study of 38,094 Dutch men and women ages 20 – 70 it was found that vitamin K2 intake had a statistically significant inverse relationship to the risk of developing type 2 diabetes. Vitamin K1 intake also trended in the preventive direction, though the benefit was not enough to be statistically significant. This finding corresponds to the science showing that vitamin K2 is a more potent activator of osteocalcin than vitamin K1.



Low vitamin K levels may be supplemented with 100 to 500 mcg per day.



Increased Risk of Prostate Cancer

A German study (2008) looked at the relationships between dietary intake of vitamin K1 and K2 on the development of prostate cancer in 11,319 men over a period of 8 years.

Those with the highest level of vitamin K2 intake had a 63% reduced incidence of advanced prostate cancer. The intake of vitamin K1 did not produce this effect. [Am J Clin Nutr. 2008 Apr;87(4):pp. 985-92]


Increased Risk of Lung Cancer

The European Prospective Investigation into Cancer and Nutrition – Heidelberg cohort study involving 24,340 participants aged 35 – 64. They were free of cancer at enrollment (1994-1998) were actively followed up for cancer incidence and mortality through 2008. Their vitamin K1 and K2 dietary intake was tracked over these years and compared to cancer incidence and mortality. Vitamin K2, but not vitamin K1, was inversely associated with the risk of cancer and cancer mortality. The benefit of vitamin K2 was greatest for men, with a notable reduction in prostate and lung cancer.


Increased Risk of Coronary Disease / Heart Attack

One potential link between vitamin K and heart disease is calcification of arteries. In vitro and in vivo evidence suggest that interruption of vitamin K biological function results in abnormal arterial calcification. Specifically, interference with MGP (matrix Gla protein) function induced by vitamin K deficiency appears to be an important factor in calcification. In mice, knockout of the MGP gene results in 50% fetal death, and in live births there is marked calcification of the arterial tree as well as bone loss (osteopenia). Human data are limited primarily to case reports of individuals exposed to warfarin in utero. However, one recent study in postmenopausal women suggested that lower vitamin K status is associated with increased carotid artery calcification.

Further, it has been demonstrated that with every increase of 10 micrograms in the amount of vitamin K2 consumed daily, the risk of developing coronary heart disease (CHD) drops by 9%. This somewhat stunning statistic was noted as a result of a study from the Netherlands evaluating the dietary vitamin K intakes of 16,057 post-menopausal women and their association with the incidence of CHD.

“Of the subtypes of vitamin K2, it appeared that particularly MK-7, MK-8 and MK-9 affected the risk of CHD,” said the researchers. “A stronger effect of the longer subtypes could be due to a slower hepatic clearance of these subtypes, making them longer available for carboxylation reactions.” [Nutrition, Metabolism and Cardiovascular Diseases

Published online 28 January 2009


Tumors, Malignant  

Multiple Myeloma

Many patients on high dose chemotherapy for lymphoma or myeloma test positive for prothrombin precursor PIVKA II. These are proteins induced by vitamin K absence or antagonism.


Non-Hodgkin's Lymphoma

Many patients on high dose chemotherapy for lymphoma or myeloma test positive for prothrombin precursor PIVKA II. These are proteins induced by vitamin K absence or antagonism.



Menorrhagia (Heavy Periods)

Based on its ability to help blood clot normally, vitamin K has been proposed as a treatment for excessive menstrual bleeding and is beneficial for some women. Although bleeding time and prothrombin levels in women with menorrhagia are typically normal, the use of vitamin K (often in the form of chlorophyll) does have limited research support. Green leafy vegetables and other sources of vitamin K should be eaten freely.


May do some good
Likely to help
Highly recommended
Reasonably likely to cause problems


Vitamin K

Helps the blood clot when the body is injured.


(mcg): 1/1,000 of a milligram in weight.


(mg): 1/1,000 of a gram by weight.


Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.


The body's most abundant mineral. Its primary function is to help build and maintain bones and teeth. Calcium is also important to heart health, nerves, muscles and skin. Calcium helps control blood acid-alkaline balance, plays a role in cell division, muscle growth and iron utilization, activates certain enzymes, and helps transport nutrients through cell membranes. Calcium also forms a cellular cement called ground substance that helps hold cells and tissues together.


A substance that prevents or delays blood clots (coagulation).


An essential mineral that our bodies regulate and conserve. Excess sodium retention increases the fluid volume (edema) and low sodium leads to less fluid and relative dehydration. The adult body averages a total content of over 100 grams of sodium, of which a surprising one-third is in bone. A small amount of sodium does get into cell interiors, but this represents only about ten percent of the body content. The remaining 57 percent or so of the body sodium content is in the fluid immediately surrounding the cells, where it is the major cation (positive ion). The role of sodium in the extracellular fluid is maintaining osmotic equilibrium (the proper difference in ions dissolved in the fluids inside and outside the cell) and extracellular fluid volume. Sodium is also involved in nerve impulse transmission, muscle tone and nutrient transport. All of these functions are interrelated with potassium.

Clotting Factors

Substances in the bloodstream, especially vitamin K, that are important in the process of blood clotting. Prolonged bleeding is produced when these substances are absent.


Microscopic germs. Some bacteria are "harmful" and can cause disease, while other "friendly" bacteria protect the body from harmful invading organisms.


Pertaining to the stomach, small and large intestines, colon, rectum, liver, pancreas, and gallbladder.


The prostate gland in men that surrounds the neck of the bladder and the urethra and produces a secretion that liquefies coagulated semen.


Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.


A disease in which bone tissue becomes porous and brittle. The disease primarily affects postmenopausal women.


(gm): A metric unit of weight, there being approximately 28 grams in one ounce.

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