Vitamin K can now be added alongside vitamin D as an essential nutrient in which deficiencies have been linked to worse outcomes with COVID-19 patients.

To be clear, there is currently no cure for COVID-19, no vaccine yet developed. Supplements cannot claim to prevent, cure or treat any disease.

Vitamin D has benefited from 22 published human clinical studies since the coronavirus outbreak began; these studies show that elevated levels of vitamin D improve clinical outcomes or at least mitigate the worst outcomes, while deficiency levels makes things worse.

With vitamin K, researchers in a new study started from the observation that vitamin K deficiency might be related to worse COVID-19 outcomes, given that patients with severe COVID-19 are more likely to have so-called co-morbidities such as type 2 diabetes, hypertension and cardiovascular diseases—all of which are associated with reduced vitamin K levels.

Not only is cardiovascular disease linked to low vitamin K status, but it also includes a breakdown of tissue fibers as measured by elastin, which is involved with pulmonary disease—and severe COVID-19 patients seem to use stores of vitamin K to protect the partially degraded elastic fibers in the lungs.

Researchers also noticed the connection between patients with severe COVID-19 symptoms and a bleeding disorder called coagulopathy, in which the blood’s ability to form clots is impaired. These patients also suffer from thromboembolism, wherin dislodged blood clots block blood vessels. Vitamin K is most renowned for its ability to coagulate the blood—the process of promoting and dissolving blood clots.

They thus hypothesized that vitamin K status is reduced in patients with severe COVID-19.

They looked at 123 COVID-19 patients and 184 controls. And they found a clear connection.

"The study represents an amazing finding," explained Leon Schurgers, professor of biochemistry of vascular calcification and vice chair of biochemistry at the Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, and co-author of the study. "This study illustrates that a poor vitamin K status–deduced from low dp-ucMGP levels–is linked to poor prognosis.

The study concluded that vitamin K status was reduced in patients with COVID-19 and related to poor prognosis. importantly, vitamin K levels were significantly lower in COVID-19 patients compared to healthy controls, as has been shown in patients with co-morbidities. Also, low vitamin K status seemed to be associated with accelerated elastin degradation. In conclusion, vitamin K status was reduced in COVID-19 patients compared to controls and was associated with disease severity.

While inspired by the results, the study authors remained cautious.

"It might be tempting," wrote the study authors, "to speculate that vitamin K administration has an improving effect on vitamin K status in severe COVID-19 patients. However, this has never been studied in this patient group. Additionally, whether improving vitamin K status would correlate with better prognosis in SARS-CoV-2-infected individuals has to be tested. Preliminary evidence was provided suggesting a potential mechanistic link between reduced vitamin K status and accelerated tissue degradation. An intervention trial is now needed to assess whether vitamin K administration improves outcome in patients with COVID-19."

The researchers are currently measuring blood levels of vitamin D in the COVID-19 pateints to see if there is any connection there as well.

The vitamin K2 connection

Because of the clear vitamin K connection, the researchers also hypothesized that vitamin K2 (not to be confused with vitamin K) could be linked to better health outcomes in these cases.

Vitamin K2 has an integral role in activating and binding calcium to bones, and it also keeps calcium from accumulating in the walls of blood vessels—atherosclerosis, or hardening of the arteries, is the top cardio killer.

Simply put, vitamin K2 takes calcium from wher you dont want it (arteries) and puts it wher you do want it (bones). Pretty nifty trick.

The vitamin K2 connection is also correlated because it is found naturally in real cheese (not "American cheese") as well as in natto—a funky fermented soy dish that’s a staple of Japanese breakfasts. One study researcher said it "may be very relevant" that Japanese regions in which natto consumption is high reportedly have less COVID-19 incidence and disease severity.

Interestingly, one key factor in the study is the measurement of vitamin K status determined by the amount of the "inactive" vitamin K-dependent protein, Matrix Gla Protein, or MGP.

What makes that interesting is that vitamin K2 has been found to activate vitamin K-dependent proteins including MGP. The most widely studied brand of vitamin K2 is the MenaQ-7 brand owned by NattoPharma. The company has sponsored 19 published studies into MenaQ-7 brand vitamin K2.

According to the study, vitamin K-dependent MGP is generally accepted as an inhibitor of vascular calcification, and there are scientific leads suggesting that MGP also plays a role in the creation of lung fibrosis. MGP is crucial for the protection of elastic fibers against mineralization and fibrosis may be present in lungs of patients with severe COVID-19.

Also, low dp-ucMGP levels were significantly correlated with desmosine levels, a measure of the breakdown of elastin, which is an important factor for pulmonary health.

"Supplementation of vitamin K increases the vitamin K status in the body as measured by the level of active vitamin K-dependent proteins, and vitamin K2 is clearly the best form of vitamin K due to its superior bioactivity," said Hogne Vik, chief medical officer at NattoPharma. "MGP is the most potent known inhibitor of vascular calcification to date. MGP is a K-dependent protein already present in the body, but it needs adequate vitamin K2 to be activated to perform its function."

The lead researcher, Rob Janssen, applied for a patent for vitamin K status as a prognostic and therapeutic biomarker in COVID-19.