Numerous studies have shown that healthy levels of vitamin D significantly lower your chances for severe Covid-19. A paper published in September 2020 has shown that people with lower vitamin D levels are significantly more likely to test positive for coronavirus.

The study’s lead researcher, Dr. Michael Hollick, is widely considered one of the world’s leading experts in vitamin D. Hollick’s team used retrospective observational analysis of COVID–19 tests to determine whether or not vitamin D levels in the blood impacted test results.

Related: COVID Second Wave Is Happening All Over Europe, Except in Sweden

Data was collected from 191,799 patients in all 50 U.S states from March to June 2020. The data showed that those with a vitamin D level of at least 55 ng/mL had a 47% lower positivity rate than those who had levels below 20 ng/mL. Data showed that the risk of Covid-19 continued to decrease until vitamin D levels reached 55 ng/mL.

This is only the most recent of many studies that have linked higher vitamin D levels to less severe cases of COVID-19.

An Iranian study published online in mid-July 2020 also found that patients with vitamin D levels above 30 ng/mL (75 nmol/L) had better clinical outcomes and a far lower risk of death. Among COVID-19 patients over the age of 40 who had vitamin D levels below 30 ng/mL, 20% died, compared to 9.7% of those with levels at or above 30 ng/mL. Among those with a vitamin D level of at least 40 ng/mL, only 6.3% died.

Vitamin D Cuts SARS-CoV-2 Infection Rate by Half

Related: Coronavirus Supplement Review

If you’re worried about coronavirus, vitamin D can help. However, your primary focus should be gut health. If you eat a diverse diet that promotes gut health (a big salad every day) and get enough sunlight, your vitamin D levels, along with your other vitamin levels should be more than sufficient to prevent COVID-19.