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) includes menaquinone-4 (MK-4) and menaquinone-7 (MK-7).
The Benefits of Vitamin K
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, Vitamin K2 is especially beneficial for conditions such as atherosclerosis, arterial calcification, and osteoporosis. [1,2]
Over the last 40 years, researchers have discovered that Vitamin K2 is associated with a reduction in the prevalence of cardiovascular mortality. [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 enables the body to deliver more oxygen. [4]
Vitamin K and Coagulation
Vitamin K plays a crucial role in supporting healthy blood coagulation, as it carboxylates several clotting proteins in the liver, including clotting factors II (prothrombin), V, VII, and IX. [5]
Vitamin K and Cancer Prevention
Evidence suggests that Vitamin K inhibits cellular growth in several types of cancer. [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 the arteries back into the bone, which is particularly important for higher-risk groups, such as postmenopausal women.
Research into MK-7, using DXA measurements, has shown significant improvements in reducing the decline in bone mineral content, density, and bone strength, as indicated by Vitamin K. [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 crucial role in the synthesis of sphingolipids, a group of lipids essential for the formation of the myelin sheath and brain cells. [11]
Additionally, Vitamin K-dependent proteins play a crucial role in supporting the health of the central and peripheral nervous systems by promoting 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 a crucial role in the production of cellular energy, helping to maintain normal ATP production. [13]
This suggests that Vitamin K2 may play a role in treating diseases associated with 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 by modulating osteocalcin and the function of beta cells in the pancreas, as well as by 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 type 2 diabetes. [17,18]
A large study involving 38,000 men and women, aged 20 to 70, found that 10 µg per day of Vitamin K2 reduced the risk of type 2 diabetes by 7%. [18]
What Foods Contain Vitamin K?
Plants naturally synthesise Vitamin K1. Foods rich in Vitamin K can be found in high concentrations in leafy green vegetables, such as collard greens, kale, broccoli, and spinach. [9]
Whereas, Vitamin K2 can only be produced by bacteria in fermented foods, such as cheese, curds, and sauerkraut, as well as in animal products like meat, eggs, and liver. [5,9]
Vitamin K High Foods
The best natural source of foods rich in Vitamin K includes natto, which contains approximately 1,100 mcg of Vitamin K2 in a 100-gram 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 essential to note that only 20% of dietary K1 is absorbed, and although it can be converted to K2, the efficacy of this conversion 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, 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, 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 considered safe for use during pregnancy and breastfeeding, and there have been no adverse events or risks identified in humans, the research is limited or unavailable; therefore, a tolerable upper intake level is not conclusive. [27,28]