Vitamin D has long been a useful warrior in the fight against disease, but now some studies are hinting that it might help fight COVID-19.

In this day and age, everyone is desperately looking for a cure, the Internet is rife with misinformation, and nothing is certain about vitamin D yet. But several promising studies have found that lower levels of vitamin D can put patients at increased risk of death from COVID-19, while higher levels might increase patients' chances of survival.

An April 9 study from the Philippines measured vitamin D levels in 212 coronavirus patients and found that patients with lower Vitamin D levels had relatively mild symptoms, while patients with deficiencies tended to grow much sicker. Prior to that, an Indonesian study from May said that "majority of the COVID-19 cases with insufficient and deficient vitamin D status died."

A similar study from Northwestern University explored 10 countries and also "found a correlation between low vitamin D levels and hyperactive immune systems." Most recently, a new study from Trinity in Ireland came to the same conclusions, also finding that lower levels of vitamin D are linked to a higher mortality rate for COVID patients.

Vitamin D plays an important role in the body's immune response. It may also be able to help heal compromised respiratory functions, according to Newsweek. COVID-19 is still a relatively unknown disease, but it is believed that the virus creates what's called a cytokine storm in patients. That means that the body produces a superabundance of messenger proteins called cytokines, which can lead to inflammation in the lungs. Vitamin D can help prevent the release of cytokines.

These studies are inconclusive, and clinical trials are just beginning. "If vitamin D levels are really a marker for better diet, or more access to healthcare, or any of a variety of other variables that are not statistically assessed, then it is not the vitamin D that is the cause of the better or worse outcomes but rather the other factors," said Daniel Culver, Director of the Interstitial Lung Disease Program in the Department of Pulmonary, Medicine at the Cleveland Clinic.

To be clear, vitamin D is not a miracle cure. "We found no clinical evidence on vitamin D in COVID-19," scientists from Oxford University wrote after their study. "There was no evidence related to vitamin D deficiency predisposing to COVID-19, nor were there studies of supplementation for preventing or treating COVID-19."

Still, because it's relatively harmless, some countries are now calling for widespread dissemination of vitamin D supplements and advising people to pay attention to their own levels. It's important to note that it is possible to ingest too much vitamin D, but a few supplements, some eggs, or some extra (safe) sunshine is probably as good a prescription as any during these isolated times.