“People have been looking for the magic drug or waiting for the vaccine and not looking for something this simple,” said Dr Michael Holick, professor of medicine, physiology and biophysics at Boston University School of Medicine, reports Bostom Herald.

Holick and his colleagues studied blood samples from Quest Diagnostics of more than 190,000 Americans from all 50 states and found that those who had deficient levels of vitamin D had 54% higher COVID positivity compared to those with adequate levels of vitamin D in the blood.

The risk of getting coronavirus continued to decline as vitamin D levels increased, the study, published in the Public Library of Science One peer-reviewed journal shows.

“The higher your vitamin D status, lower was your risk,” Holick said.

Many people are vitamin D-deficient because there are only small amounts in food, Holick said. Most vitamin D comes from sun exposure and many are deprived, especially during winter months.

But the sunshine vitamin is easy to find and relatively cheap in drug stores, and taking vitamin D pills comes at no risk. “It’s perfectly safe,” Holick said.

“It’s considered to be, by many, the nutrient of the decade,” Holick said.

COVID-19 positivity is strongly associated with vitamin D levels in the blood, a relationship that stayed the same across different races, sexes and age ranges, the study states.

Also read: Higher Vitamin D in 1st year of life can help against obesity in adolescence: study

Vitamin D suppresses excessive cytokine release that can present as a cytokine storm, a common cause of COVID-related morbidity and mortality.

A deficiency in the nutrient alters the immune system, making one more likely to get upper respiratory infections, Holick said.

Throughout the pandemic, people of color have been disproportionately affected by coronavirus, experiencing a higher risk of acquiring it and having serious complications, according to the Centers for Disease Control.

Holick’s study examined the ZIP codes of people of color and found patients from predominantly Black and Hispanic ZIP codes had lower levels of vitamin D and were also more likely to have coronavirus than in patients from predominantly white, non-Hispanic ZIP codes.

The average adult needs around 2,000 units of vitamin D a day, Holick said. He said he’s been taking 6,000 units a day for decades and is in great health.

Several other studies on vitamin D have shown its benefits to the immune system.

Also read: Vitamin D deficiency may increase risk of getting Covid-19: Study

Research published with the National Institutes of Health showed people with lower vitamin D levels were more likely to self-report a recent upper respiratory tract infection than those with sufficient levels.

Another study of more than 11,000 participants published in the British Medical Journal found vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants.

“Vitamin D definitely improves your overall immunity to fight infections,” Holick said.

Update:  A Brigham and Women’s Hospital study will test to see if vitamin D can lessen the severity of coronavirus symptoms and reduce the chance of becoming infected with the illness in a nationwide, placebo-controlled trial.