Vitamin K and heart health in relation to COVID-19

Vitamin K and heart health

Experts are recommending that people do what they can to boost their immune systems to work on their immunity and strengthen their defense mechanisms to better combat infection and spread of this virus. 

According to a recent study conducted in partnership with the Cardiovascular Research Institute Maastricht, foods rich in vitamin K have been helpful in the battle, and a deficiency may worsen the symptoms of COVID-19. 

This virus is known to cause degradation of elastic fibers in the lungs as well as blood clots, vitamin K has been shown to be helpful in the production of proteins that regulate clotting. As such experts have linked the consumption of foods that are rich in vitamin K to blood vessels, bones, and the lungs. 

Including more foods in your diet that are rich in vitamin K may help to reduce the risk of COVID-19 complications, as well as helping to improve your overall health. There are two main forms of this vitamin: K1 (phylloquinone found in plant based foods) and K2 (menaquinone found in fermented in animal products). Many green vegetables are rich in vitamin K such as leafy greens like spinach, kale, broccoli, and cabbage. 

Just one cup of spinach can be enough to meet the daily nutritional recommendation value for vitamin K. Soybeans are a rich source of vitamin K2. Fish is another good source of vitamin K. Eggs and dairy are good sources of vitamin K, particularly cheese but non-fermented cheeses like processed cheese contain very low amounts of vitamin K. 

It is even suggested that the rare vitamin K may be the missing link between diet and several chronic diseases. Originally vitamin K was known as the essential element of blood coagulation which was dubbed Koagulationsvitamin and shortened to vitamin K. 

This vitamin activates proteins that play roles in blood clotting, calcium metabolism and heart health. One of its functions is to regulate calcium deposits to promote calcification of bones and prevent the calcification of blood vessels and the kidneys. It may help to prevent heart disease by preventing calcium from being deposited in the arteries. 

As it plays essential roles in bone metabolism, studies suggest that it may help to prevent osteoporosis and fractures. Vitamin K is also speculated to affect dental health, but human studies showing the benefit to dental health are lacking.

The benefits of supplementing vitamin K may be further enhanced when combined with a vitamin D supplement because these vitamins have synergistic effects. 

How vitamin K and vitamin D can prevent heart disease and stroke

This is how and why vitamin D and K work together Vitamin D is a hormone. It changes the gene expression in your intestinal cells and allows them to bind more calcium and pull it in to the body. When you have low levels of vitamin D, you get around 10-15% absorption of calcium. 
When you have higher levels of vitamin D, you get between 30-40% absorption of calcium. If you are taking 1000-1500mg of calcium and 3,000-5,000 IU of vitamin D every day, you are getting a lot of calcium circulating in your body. 
This is where K2 comes in. K2 is used by the body to make a series of proteins that will protect the body from excess calcium. Two such proteins are called osteocalcin and matrix GLA protein or MGP. 
Osteocalcin, after being primed by vitamin K2, will bind to calcium and put it in the bones. Matrix GLA Protein (MGP), after being primed by K2, will sweep through the soft tissues of the body (think blood vessels) and clean up any calcium that deposited itself there. In essence, these two proteins keep calcium out of the vessels and put it in the bones. 
When we do not have enough vitamin K2 around, calcium can accumulate in the vessels that lead to the heart and the brain, thus increasing the risk of having a heart attack or stroke.
On the opposite end of the spectrum, human studies are demonstrating the ability of increased levels of vitamin K2 to decrease arterial calcification and cardiovascular deaths.

How do you know if vitamin K2 deficiency is an issue for you?

You know to be deficient when you
  • suffer from a digestive disorder that can lead to fat soluble vitamin insufficiencies (Small Intestinal Bacterial Overgrowth or SIBO, Irritable Bowel Syndrome, Inflammatory Bowel Disease, Celiac Disease, Cystic Fibrosis)
  • have osteoporosis or osteopenia
  • have tooth decay
  • have elevated blood pressure
  • experience calcification of the aorta, coronary arteries, or carotid artery
  • experience calcification of the muscles, joints (osteoarthritis), tendons (calcific tendonitis), kidneys, or brain
  • have had a previous stroke
  • have had a previous heart attack
  • have a diet low in liver, natto (fermented soybean preparation), pastured dairy (especially cheeses), and egg yolks
  • are taking a high dose vitamin D supplements >3000IU per day without supplementing with vitamin K
  • have chronic kidney disease and/or are on dialysis

If you have signs of deficiency, you will likely benefit from increasing your intake of vitamin K2 containing foods and supplements.

Higher vitamin K intake has positive health effects

In 2004, nearly 5000 persons were evaluated for vitamin K intake. People eating foods with a high K2 content had up to a 52% decrease in arterial calcification. They also had up to a 57% decrease in death from heart disease.  The foods most associated with the decreased rates were meats, eggs, sauerkraut, fish, cheese, and other dairy products. Note: pastured/grass fed dairy product have higher levels. 
Two scientific trials confirmed these findings with one showing a 20% decrease in coronary artery calcification with higher vitamin K2 intake and the second approximated a 9% decrease in coronary heart disease for every 10mcg of vitamin K2 that was ingested per day. 
Supplementation with K2 appears to be effective as well. When 180mcg of MK7 was taken every day for 3 years by healthy postmenopausal women, it improved arterial stiffness. 


There are two types of vitamin K2 that most people refer to when they talk about supplementation: MK4 and MK7.
MK4 is has a very short half-life (1-2 hours) so large doses at frequent intervals are required for optimal results. Numerous trials have shown benefit with bone health when people supplement 15mg of MK4 three times a day. 
MK7 has been found in the body up to 72 hours after dosing and appears to be even more efficient at lowering vitamin K dependent proteins than MK4. Therefore, smaller dosing is needed (100-400mcg). The cost of supplementation is usually considerably lower with MK7.
Vitamin K supplementation is considered safe, and there are no toxic upper limits for either vitamin K1 and K2.
It appears that each form of vitamin K is used differently in various tissues and organs of the body so a combination of various vitamin K forms from supplements and the diet may be ideal. 
If you are taking the blood-thinning medication called Warfarin or Coumadin, you must consult with your primary care physician before taking any vitamin K or increasing vitamin K-rich foods in your diet, because all forms of K2 will alter clotting factors. 
Your physician will have to monitor you very carefully when vitamin K intake is increased. 
There is some interesting research though that indicates how small doses of MK7 (<45mcg per day) may be used to protect people that are using these medications to prevent calcification of their vessels.


Although more research is required on vitamin K, which may have life saving implications for some people, it is clear that it plays an essential role in body functions. To maintain good health it is recommended to ensure that you get enough vitamin K through your diet, which will in turn boost your immune system.


The reason we wrote this article: Reduced Vitamin K Status as A Potentially Modifiable Prognostic Risk Factor in COVID-19

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