Patients who died or were admitted to intensive care units with Covid-19 were found to be deficient in Vitamin K, which is found in spinach, eggs, and certain cheeses, according to a study.
This has raised hopes that dietary change might be the key to combating coronavirus, reports The Guardian.
Researchers have discovered a possible link between deficiency of Vitamin K and the worst coronavirus outcomes as they studied patients admitted to the Canisius Wilhelmina hospital in Nijmegen, a city in the Netherlands.
The study was undertaken in partnership with the Cardiovascular Research Institute Maastricht, one of Europe's largest heart and vascular research institutes, and was submitted for peer review on Friday.
Covid-19 causes blood clotting and leads to the degradation of elastic fibres in the lungs. Vitamin K is key to the production of proteins that regulate clotting and can protect against lung disease.
The vitamin is ingested through food and absorbed in the gastrointestinal tract.
Dr Rob Janssen, a scientist working on the project, told The Guardian that based on the initial findings he would encourage a healthy intake of Vitamin K, except to those who are on blood-clotting medications such as warfarin.
"We are in a terrible, horrible situation in the world. We do have an intervention which does not have any side effects, even less than a placebo. There is one major exception: people on anti-clotting medication. It is completely safe in other people," he said.
"My advice would be to take those vitamin K supplements. Even if it does not help against severe Covid-19, it is good for your blood vessels, bones and probably also for the lungs.
"We have [vitamin] K1 and K2. K1 is in spinach, broccoli, green vegetables, blueberries, all types of fruit and vegetables. K2 is better absorbed by the body. It is in Dutch cheese, I have to say, and French cheese as well," Janssen added.
A type of fermented soya beans called natto, a Japanese delicacy, is particularly high in Vitamin K2 and its health benefits may be studied further, Janssen told The Guardian.
"I have worked with a Japanese scientist in London and she said it was remarkable that in the regions in Japan where they eat a lot of natto, there is not a single person to die of Covid-19; so that is something to dive into, I would say," Janssen said.
The research studied 134 patients hospitalised for Covid-19 between March 12 and April 11, alongside a control group of 184 age-matched patients who did not have the disease.
"We want to take very sick Covid-19 patients and randomise so that they get a placebo or Vitamin K, which is very safe to use in the general population. We want to give vitamin K in a significantly high enough dose that we really will activate [the protein] that is so important for protecting the lungs, and check if it is safe," Jona Walk, another researcher on the study, told The Guardian.
The Dutch researchers are now seeking funding for a clinical trial based on the study.