During President Trump’s bout with coronavirus, along with the treatment he was given – notably the antiviral drug Remdesivir and the experimental Regeneron antibody cocktail – he also took a handful of over the counter supplements, including Vitamin D.

There has been growing interest in the sunshine vitamin and mounting evidence that it could potentially play a role in protecting against COVID-19. 

University of Pennsylvania Nutrition Researcher Ronan Lordan recently helped pen a COVID-19 review, on the link between inflammation and how good nutrition may help to reduce it. He says the nutrients we do or don’t get, could play a role in how the immune system responds to COVID-19. But Lordan cautions that more research is still needed. Confirming that link, he says, is not the priority at the moment.

“The main scientists that are out there, like Dr. [Anthony] Fauci, they're not giving a whole lot of credence to this right now. And the reason is because we need to focus on vaccines and the preventatives that we know work, like washing your hands, social distancing and so on,” said Lordan. “For scientists of course, this is a really interesting rabbit hole to go down because it's cheap and could be effective.”

There is burgeoning research out of the University of Chicago on a potential link between Vitamin D deficiency and worse COVID-19 outcomes.

Dr. David Meltzer, chief of hospital medicine for the the University of Chicago who authored the study, said he and his colleagues looked at the records of patients coming into the hospital for COVID-19 tests to see if there was a correlation.

“What I discovered is that, controlling for race and body weight and comorbidities,” Meltzer said. “That patients who were Vitamin D deficient had a 77% increase in the likelihood of testing positive for COVID if they were Vitamin D deficient.”

Meltzer believes his work supports previous research done showing that Vitamin D can be protective against respiratory illnesses. He says Vitamin D can control genes that influence the immune system, strengthening its ability to fight against pathogens it has never seen before.  

“It also has been shown to play a role in adaptive immunity, which is your ability to mount an enhanced immune response when you're exposed again to something you have seen before then or in response to a pathogen. And then finally, Vitamin D has been shown to play a role in immunomodulation, which is preventing the immune system from becoming hyperactive,” said Meltzer.

Meltzer is referring to a hallmark of COVID-19 illnesses, the “cytokine storm,” or a similar type of overreaction of the immune system known to cause extensive inflammation, which can damage the lungs and other organs.

Still, studies like Meltzer’s are taken with a grain of salt by some, because the Vitamin D data used is from a patient’s past history.

“Most of these are retrospective. These are very different from saying I am going to randomize patients to get Vitamin Dor not get Vitamin D, and see what happens,” said NYU Langone Health Pulmonologist Daniel Sterman. “The way we prove something in medicine is by doing randomized, typically placebo controlled clinical trials.” There are no completed randomized controlled COVID-19 trials for vitamins and supplements, yet.

Meltzer said they are trying to recruit patients for randomized Vitamin D trials. He said in the meantime, public health officials should consider recommending that people in high risk categories, particularly the elderly, Black and Latinx Americans, and even those who work at night take Vitamin D supplements anyway. Those in the above mentioned groups have higher rates of Vitamin D deficiency.

“At reasonable doses, Vitamin D is already recommended for people to take as a supplement to improve their bone health and general health,” said Meltzer. “I think it's a risk benefit situation. We waited a very long time to make recommendations about masking. And what's the downside of a mask? I know there are people who don't like them, but it's a piece of cloth on your face.”

To those who have been touting Vitamin D as the answer to this crisis, Meltzer says it’s not a cure-all. “No one should take Vitamin D and then go out and take off their mask and put themselves in high risk positions. That's not logical if you don't want to get covid. But, you know, it's a valuable thing that potentially could help many of us.”

Dr. Elizabeth Bradley is the medical director for the Cleveland Clinic’s Center for Functional Medicine. With so little data available on preventative therapies and supplements for COVID-19, she says the best thing people can do is focus on eating healthy.

Bradley says the Mediterranean diet is a good start. “It’s high in antioxidants, and inherently it is anti-inflammatory. So you're having a lot of the mono and saturated fats with olive oil, you're having lots of fruits and vegetables, low or no processed foods, almost no red meat, having small moderate amounts of fish, poultry, nuts, seeds, grains and whole grains.”

With seniors often found to be deficient in micro and macronutrients, and many Americans living with obesity and diabetes, the pandemic Bradley says should inspire a closer look at how we are all living.

“It’s a multifaceted approach like everything in life; it's the vaccine, it's actually having proper treatment,” said Bradley. “And I think the preventative side goes to what are we seeing; more than 50 percent of Americans are obese or overweight. And if we can even touch that part of it, that alone will probably make their risk of getting [covid-19] or the outcome, less severe. We should start now, because we know the virus is not going away.”