What are the Health Benefits of Vitamin K?
What is Vitamin K?
Vitamin K is a group of fat-soluble vitamins consisting of two key forms:
Vitamin K1 (phylloquinone)
Vitamin K2 (menaquinone), which includes menaquinone-4 (MK-4) and menaquinone-7 (MK-7).
Vitamin K and Cardiovascular Disease
Vitamin K2 is well known for maintaining heart health by preventing the build-up of calcium in your soft tissues, arteries and veins. [1,2]
As a result, this makes Vitamin K2 especially beneficial for conditions like atherosclerosis, arterial calcification, and osteoporosis. [1,2]
In the last 40 years, researchers have realised that Vitamin K2 has been associated with reducing the prevalence of cardiovascular mortality rate. [3]
Vitamin K has been shown to support cardiac output. This is the volume of blood being pumped out of the heart per minute, which results in the body's ability to deliver more oxygen. [4]
Vitamin K and Coagulation
Vitamin K plays a key role in supporting healthy blood coagulation, as it carboxylates several clotting proteins in the liver, including clotting factor II (prothrombin), V, VII and IX. [5]
Vitamin K and Cancer Prevention
Evidence indicates that Vitamin K inhibits the cellular growth in several cancers. [6] This includes hepatocellular carcinoma, leukaemia, colorectal, ovarian, pancreatic, and lung cancers. [7]
Mechanisms include induced apoptosis and cell cycle arrest of cancer cells. [7]
Vitamin K and Osteoporosis
When it comes to bone health, Vitamin K2 regulates bone remodelling, while supporting bone density, mass and integrity, and therefore providing a protective action against bone loss. [8,9]
Vitamin K directs calcium from arteries back into bone, which is important for higher-risk groups such as postmenopausal women.
Research into MK-7, using DXA measurements, Vitamin K showed significant improvements in reducing the decline in bone mineral, content, density and bone strength. [10]
Vitamin K and Myelin Sheath Function
Healthy nerves require a strong myelin sheath, which is the protective coating that insulates the nerves and conducts the electric signals throughout the entire nervous system. [11]
Vitamin K2 plays a vital component in the synthesis of sphingolipids, which is a group of lipids important for the formation of the myelin sheath and brain cells. [11]
In addition, Vitamin K–dependent proteins are involved in supporting the health of the central and peripheral nervous systems through the induction of mitosis and the growth of neurons and glial cells. [11]
Research suggests that alterations in the metabolism of sphingolipid formation may be linked to inflammation and neurodegenerative disorders, such as Alzheimer’s disease and Parkinson’s disease. [12]
Vitamin K2 and Mitochondrial Health
Vitamin K2 plays an integral role in the production of cellular energy while helping to maintain normal ATP production. [13]
This could suggest that Vitamin K2 could play a part in the treatment of diseases linked to mitochondrial pathologies, such as Parkinson’s disease and amyotrophic lateral sclerosis. [14]
Vitamin K and Blood Glucose Metabolism
Vitamin K is thought to regulate glucose metabolism in insulin resistance and diabetes through modulating osteocalcin and the function of beta cells in the pancreas and reducing pro-inflammatory cytokines. [15,16]
Vitamin K and Diabetes Type 2
The long-term supplementation of Vitamin K2 has been shown to reduce the risk of developing diabetes type 2. [17,18]
A large study with 38,000 men and women, aged 20 to 70, established that 10 µg per day of Vitamin K2 decreased diabetes type 2 risk by 7%. [18]
What Foods Contain Vitamin K?
Plants naturally synthesise Vitamin K1. Foods that contain Vitamin K can be found in high concentrations in leafy green vegetables like collard greens, kale, broccoli, and spinach. [9]
Whereas, Vitamin K2 can only be produced by bacteria in fermented foods, such as cheeses, curds and sauerkraut, and in animal products such as meat, eggs and liver. [5,9]
Vitamin K High Foods
The best natural source of foods with high Vitamin K includes natto, with approximately 1,100 mcg of Vitamin K2 in an approximate 100-gram per serving.
Natto is a traditional Japanese dish consisting of fermented soybeans. It has a distinctive sticky texture with a somewhat pungent smell, which can make it significantly challenging.
Interestingly, gut bacteria created through the fermentation process can produce many forms of Vitamin K2, the most commonly studied being menaquinone-4 (MK-4) and menaquinone-7 (MK-7).
Other good food sources of Vitamin K2 include goose liver, various organ meats, and soft cheeses like Gouda and Brie, which contain Vitamin K2 in its menaquinone-4 form (MK-4). [5]
Unfortunately, these foods have a short half-life of roughly 4-6 hours, which means you would need to consume these foods every 4-6 hours to maintain optimal K2 (MK-4) levels.
Absorption of Vitamin K
It is important to note that only 20% of dietary K1 is absorbed, and although you can convert K1 to K2, the efficacy is only between 5% and 25%. [1]
Studies have compared the body’s ability to absorb Vitamin K and the results indicate MK-7 is superior when compared to both Vitamin K1 and other forms of K2 such as MK-4. [19,20]
Deficiency of Vitamin K
The inadequate intake of Vitamin K is becoming increasingly common, as the typical Western diet lacks adequate sources of Vitamin K2. [21,22]
The risk of Vitamin K2 deficiency increases with age and those who may be using cardiovascular medication and experience bone health issues. [21,22]
Antibiotics destroy the bacteria or microbiome balance in your gut, thereby potentially affecting your body’s ability to produce Vitamin K.
The conversion of Vitamin K is also a factor with humans only converting between 5% and 25% of ingested and absorbed dietary K1 to K2. [23]
Medications like statin cholesterol-lowering drugs can also inhibit the synthesis of Vitamin K2, and therefore potentially accelerating coronary artery calcification and affecting blood glucose levels. [1,22,24]
Vitamin K Supplements
Since K2 can’t be found in sufficient quantities in the standard Western diet, and therefore supplementation becomes necessary.
With a large number of synthetic formulations of MK-7 on the market, it’s important you choose a non-synthetic Vitamin K supplement that has been naturally fermented from natto (soybean) Bacillus subtilis spores.
Vitamin K and Warfarin
Warfarin and indandione anticoagulants work by inhibiting the conversion of the Vitamin K epoxide back to Vitamin K.
Excessive Vitamin K intake will interfere with the anticoagulant effect of these drugs unless closely monitored, and adverse effects can be rapid and serious. [25,26]
Vitamin K in Pregnancy and Breastfeeding
Although Vitamin K is appropriate for use during pregnancy and breastfeeding, and that there have been no adverse events or risks found in humans, the research is limited or unavailable, and therefore a tolerable upper intake level is not conclusive. [27,28]
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DR ALAIN FRABOTTA is a highly qualified and experienced integrative chiropractor and functional medicine naturopathic doctor in Sydney since 1995.
With a specific interest in the treatment, prevention, and management of complex chronic diseases, such as cardiovascular conditions.
Alain provides a holistic, person-centred, multidisciplinary, solution-focused, results-driven approach.
He integrates chiropractic, naturopathic and functional medicine, nutrition, counselling, and coaching to help you bridge the gap between your physical, mental, and spiritual health.
Alain is the leading integrative chiropractic and functional medicine naturopathic doctor in Sydney who wants to help you achieve your health and well-being goals as well as reach your full potential in life.
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