It is already known that severely affected corona patients often lack vitamin D and selenium, both of which are nutrients that are important for the immune system. A team of Danish scientists has now confirmed a Dutch study showing that lack of vitamin K is also widespread among patients with severe cases of the coronavirus. Vitamin K is mainly found in dark, leafy greens. In the body, the nutrient occurs as vitamin K1 and vitamin K2 and they have different functions. Lack of vitamin K or poor utilization of the nutrient may be a result of a poor diet or using certain types of medicine. Although there is no evidence that vitamin K can prevent or mitigate corona infections, the scientists present several interesting hypotheses.
In 1943, Henrik Dam, a Danish biochemist, was awarded the Nobel Prize in Medicine for his discovery of vitamin K. At the University of Copenhagen, Henrik Dam had been conducting research with a special class of organic compounds called sterols, of which cholesterol is the best known one. As part of his research, he observed that chickens on a sterol-free diet got hemorrhages in and under their skin. In other words, it was difficult for their blood to coagulate. Henrik Dam later found that chickens on a diet of pork liver were protected against bleeding. By isolating the individual components of pork liver, he was able to conclude that the explanation to these hemorrhages was the absence of a lipid-soluble factor in the sterol-deficient diet. In 1935, Henrik Dam wrote in the English science journal, Nature, about a new vitamin, which he named vitamin K (the K refers to “koagulation”, which is how you spell coagulation in Danish). Ever since, vitamin K has been subject to extensive research. In nature, the vitamin occurs in two lipid-soluble versions that have entirely different functions.
Vitamin K1 (phylloquinone) is important for the blood’s ability to coagulate. It is mainly found in dark, leafy greens such as parsley, spinach, and cabbage, plus avocados, and beans.
Vitamin K2 (menaquinone) is synthesized from vitamin K2 in a well-functioning gut flora. Also, there is quite a lot of vitamin K2 in sauerkraut. Other sources include liver, egg yolk, and high-fat dairy products. The vitamin is made by bacteria as part of the fermentation process. Vitamin K2 is important for making proteins that remove calcium from the bloodstream and deposit the mineral in bone tissue. That way, vitamin K2 prevents both atherosclerosis and osteoporosis. A less known fact is that vitamin K2 is important for insulin sensitivity and anti-inflammatory processes.
|COVID-19 is a type of coronavirus that was discovered in Wuhan, China, in December 2019|
Less vitamin K meant worse development of the COVID-19 infection
Both the Dutch and the Danish studies are observational studies where scientists looked at patient data taken from a database and compared the data to control groups.
In the Dutch study, the researchers looked at 135 hospitalized COVID-19 patients and compared them to a control group with 184 people. Levels of vitamin K in the hospitalized patients turned out to be nearly three times as low as levels in the healthy controls. The lower the vitamin K levels in the hospitalized patients, the more serious their infections got.
In the Danish study, the researchers looked at 138 hospitalized COVID-19 patients and compared them to a group of 140 healthy controls. It turned out that vitamin K2 levels in the COVID-19 patients were only around half of the levels found in healthy controls. Furthermore, the 43 patients who died of their infection had substantially lower vitamin K levels in their blood on average than the patients who survived.
|The main role of vitamin K is to function as a co-factor in the production and activation of a host of different vitamin K-dependent proteins|
Why is lack of vitamin K so common among patients with severe COVID-19?
It remains to be answered why lack of vitamin K is particularly widespread among severely affected COVID-19 patients. However, it is an established fact that older and overweight people in the risk groups generally have lower vitamin K levels in their blood. This may be because many seniors eat very little and that many overweight people have unhealthy diets with too few dark leafy greens and other good sources of vitamin K. Also, it is possible that some people have difficulty with releasing enough vitamin K from their liver stores and transporting it to different parts of the body where the nutrient is needed.
Lack of vitamin K or poor utilization of the nutrient may also occur after prolonged use of antibiotics or blood-thinning medication that works as a vitamin K antagonist to prevent blood clots. Cholesterol-lowering statins also block the body’s production of vitamin K2. Many older people and individuals who are overweight or have chronic diseases belong to the risk groups that are known to use one or several types of the listed medical drugs.
How does vitamin K protect against complicated COVID-19 infections?
It is well known that the immune system’s capacity is determining for the outcome of a COVID-19 infection and whether or not it becomes life-threatening. If the immune defense in the respiratory tract lacks vitamin D to make targeted attacks, for instance, virus will more easily replicate and spread. There is also a risk that the immune defense overreacts with cytokine storm and hyperinflammation that can damage healthy tissues in the lungs, the circulatory system, and other places.
Because vitamin K1 is important for blood coagulation and local healing processes, a deficiency of the nutrient may explain why the lungs become vulnerable during a COVID-19 infection. It is also possible that the need for vitamin K increases during an infection to ensure that there is enough to repair the damage, including the damage to the elastic fibers in lung tissue. Vitamin K2’s anti-inflammatory properties may even help protect the tissues in the lungs, cardiovascular system, and other places.
How much vitamin K do we need?
If having high levels of vitamin K can help prevent complicated COVID-19 infections, this would be a breakthrough and constitute an inexpensive therapy form, according to the Dutch and Danish scientists. However, at this point it is only a hypothesis with limited evidence. Also, we do not know how vitamin K acts in connection with an infection and we do not know what the optimal blood levels of the two types of vitamin K are.
According to Professor Allan Linneberg, who is the main author of the Danish study, there is no need to take high quantities of vitamin K. It is, however, recommended to follow the official dietary guidelines and make sure to get enough vitamin K from dark leafy greens and other sources.
The reference intake (RI) level for vitamin K is 75 micrograms for everyone aged 11 years and older. According to the most up-to-date recommendations, one must get 1 micrograms of vitamin K for every kilo of body weight in order to make sure that overweight people get enough.
According to Susanne Gjedste Bügel, a professor of clinical and preventative nutrition at the University of Copenhagen, it is perfectly safe to consume up to 500 micrograms of vitamin K per day. The Dutch scientists recommend getting more than 1,000 micrograms every day.
Who should be careful with vitamin K and supplementation?
People who are regular users of blood-thinning medication that works as a vitamin K antagonist should rely on a stable supply of vitamin K from the diet. They should not take supplements of vitamin K or consume foods that are very rich in vitamin K, unless they consult their physician. Too much vitamin K can interfere with their medicine.
Vitamin K content per 100 grams
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Frederik Guy Hoff Sonne. Forskere på sporet af corona-hypotese: Hårdt ramte patienter mangler K-vitamin. Videnskab.dk. 4. januar 2020
Helge Kragh. Fra blødende kyllinger til en nobelpris i medicin. Videnskab.dk 2017
Hyung Jin Choi et al. Vitamin K2 Supplementation Improves Insulin Sensitivity via Osteocalcin Metabolism: A Placebo-Controlled Trial. American Diabetes Care. 2011
Harumi Okuyama. Statins stimulates atherosclerosis and heart failure: pharmacological mechanism. Expert Rev Clin Pharmacol. 2015
Thomas Smith. A Supercomputer Analyzed Covid-19 – and Interesting New Theory Has Emerged. Medium. September 1, 2020
Jan Alexander et al. Early Nutritional Intervention with Zinc, Selenium and Vitamin D for Raising Anti-Viral resistance Against Progressive COVID-19. Nutrients 2020
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