There is a long-established link between nutrition and immune health. But when it comes to the coronavirus (SARS-CoV-2), scientists still don't have a definitive answer on whether certain vitamins and minerals can help stave off an infection or make one less severe.
"And that's because it's such a new phenomenon,” one that researchers are learning more about every day, says Walter Willett, M.D., professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. Nothing is known to prevent or cure COVID-19, the illness caused by the new coronavirus. However, “it's not impossible” that essential vitamins and minerals could provide some benefits, he adds.
The reason: Previous research has shown that lower-than-recommended levels of certain vitamins and minerals can impair immunity to respiratory viruses and other pathogens. Nutrient deficiencies have also been linked to higher levels of inflammation and longer periods of recovery from illness.
A few recent studies suggest an even more direct connection between certain vitamins and minerals and SARS-CoV-2. One observational report published in the Journal of Endocrinological Investigation found an association between vitamin D deficiencies and higher mortality risks from COVID-19 among patients in Italy. Another, published Sept. 3 in JAMA Open Network, found vitamin D deficiency was associated with increased COVID-19 risk. Others, yet to be peer reviewed, have drawn similar conclusions.
"The bottom line here is that I don't think anybody should be walking around with low levels or low intakes of important and essential micronutrients and minerals and vitamins at any time, but especially if they're potentially going to be infected with coronavirus,” Willett says. “It's just basically practicing good preventive nutrition to begin with.”
The nutrient gaining the most traction among scientists studying SARS-CoV-2 is vitamin D. The vitamin is found in some foods; it's also a hormone our bodies make when ultraviolet rays from sunlight strike the skin. Many know about vitamin D for its part in bone health. Equally important is its critical role in immune function, which is why it's in the spotlight with the coronavirus.
Data from countries where vitamin D deficiency is common show higher cases of COVID-19 infection and more serious health consequences from the illness, including death, says June McKoy, M.D., associate professor of medicine at Northwestern University Feinberg School of Medicine. This correlation has prompted scientists to further explore whether vitamin D has any protective qualities against SARS-CoV-2, even while other published reports dispute the link.