- Researchers from Denmark found a correlation between vitamin K deficiency and severe COVID-19 risk.
- A new study shows that people with lower vitamin D levels were more likely to experience severe illness after infection with the novel coronavirus.
- It turns out that patients who died of COVID-19 complications had even lower vitamin K levels than vitamin D.
There’s been some back and forth on the link between vitamin D and severe COVID-19, but more research has shown recently that vitamin D deficiency can increase the risk of complications from an infection with the novel coronavirus. But that’s not the only vitamin that doctors think may lead to severe versions of the illness. New research indicates that vitamin K deficiency can also be linked to more severe illness.
Danish researchers compared vitamin K levels of 138 COVID-19 patients against 140 healthy individuals. They found that patients infected with the new virus had vitamin K levels that were half the levels observed in the control group. The 43 patients who died had even lower levels than the others.
“We have investigated whether vitamin K is related to how it goes when you are hospitalized,” Allan Linneberg told a Danish TV station, via AJC. “Not whether it has anything to do with getting coronavirus.” Linneberg is a researcher at the Center for Clinical Research and Prevention at Frederiksberg Hospital.
Foods including leafy greens like lettuce, kale, and spinach, as well as vegetable oils including soybean and canola contain vitamin K. As important is it may be, however, Linnenberg cautioned against increased intake of vitamin K. ”We may need more vitamin K than we thought, but we still have to make sure we do not end up overconsumed,” he said.
Vitamin K is involved in several key processes inside the body, including coagulation and keeping blood vessels healthy. However, it’s a different vitamin K role that could explain increased COVID-19 severity in patients who have a vitamin K deficiency: the vitamin activates certain enzymes that help protect the lung tissue. “When these are not activated, the lungs become poorer and can explain why COVID-19 patients with low vitamin levels are hit hard by the illness,” Linneberg said. “However, we have not been able to ascertain whether the Vitamin K deficiency has been caused by COVID-19 or if the patients had low vitamin levels to begin with.”
The Danish study follows a study in the Netherlands from August that found a correlation between low levels of vitamin K and severe COVID-19. The Danish researchers published their study in a non-peer-reviewed form on medRxiv. “As countries worldwide are experiencing a second or even third wave of the COVID-19 pandemic, there is an urgent need for measures to improve the outcome and long-term consequences of COVID-19. Supplementation with Vitamin K represents an inexpensive and simple-to-use intervention,” the researchers wrote.
The paper also offers another hypothesis, a link between low vitamin K levels and obesity, with the latter being a risk factor for severe COVID-19. It is of potential interest that obesity is a predictor of poor outcome of SARS-CoV-2 infection. This could be in line with our recent report that obesity was strongly associated with higher levels of dp-ucMGP (indicating low vitamin K status), providing a possible explanation for the link between obesity and COVID-19.
The researchers also noted that areas of Japan with a tradition for the consumption of high vitamin K containing foods (natto) are less affected by the pandemic.
On the other hand, the paper notes some limitations that might have impacted the study, including the lack of data on vitamin D on the two cohorts. Furthermore, an actual randomized trial would be needed to prove the beneficial effects of vitamin K supplementation during COVID-19.