Vitamin D deficiency may be tied to a higher risk of severe coronavirus infection
- Vitamin D deficiency may be linked to more severe cases of the coronavirus, according to two studies based on data from more than 20 different countries.
- Researchers in both studies found that countries where people had low levels of vitamin D had a higher rate of severe COVID-19 cases and deaths than countries where people had adequate amounts of the nutrient.
- More research is needed, but this finding could help explain why some people are more vulnerable to complications from the virus than others.
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If you're looking for ways to protect yourself against the coronavirus, new research suggests that getting plenty of vitamin D could help.
Two new studies have linked vitamin D deficiency with coronavirus risks, suggesting that not having enough of the nutrient could make people more likely to experience serious complications if they are infected.
Lack of vitamin D could lead to immune system complications, worsening the virus if you do get sick, according to one study
In a study posted April 30 as a preprint, a research team led by Northwestern University looked at data on coronavirus cases in 10 countries, including China, Iran, Germany, Italy, and the US. They compared this to data on the levels of vitamin D among the population in those countries before the pandemic.
They found a strong correlation between vitamin D deficiency and severe COVID-19.
The study also found a strong correlation between vitamin D deficiency and a complication known as a cytokine storm, which occurs when the immune system goes into overdrive, worsening COVID-19 and potentially damaging the respiratory system.
"Cytokine storm can severely damage lungs and lead to acute respiratory distress syndrome and death in patients," Ali Daneshkhah, a postdoctoral research associate at Northwestern and lead author of the study, said in a press release. "This is what seems to kill a majority of COVID-19 patients, not the destruction of the lungs by the virus itself. It is the complications from the misdirected fire from the immune system."
Countries where people get adequate vitamin D could fare better against the virus
Another study also found that higher levels of vitamin D may be linked to better coronavirus outcomes.
In the study, published May 6 in Aging Clinical and Experimental Research, researchers from the UK found that countries with a higher average level of vitamin D had a lower number of coronavirus cases and a lower mortality rate from the virus. They based their study on data from 20 European countries.
Italy and Spain, for instance, had a higher mortality rate than other countries in the study, and both had a significantly lower average level of vitamin D.
Northern European countries like Finland, Norway, Denmark, and Sweden, by contrast, had the highest average levels of vitamin D among the population, and saw a lower rate of cases and deaths from the coronavirus.
Researchers noted that this study was limited in that it didn't account for the level of testing and other interventions in each country.
More research is needed to understand exactly how vitamin D influences coronavirus outcomes
The second study did not look at whether increasing vitamin D levels could lead to better outcomes for coronavirus patients. But it's a prospect researchers are interested in exploring further.
"Vitamin D has been shown to protect against acute respiratory infections, and older adults, the group most deficient in vitamin D, are also the ones most seriously affected by COVID-19," Smith said in a press release.
The results from the Northwestern study also suggest vitamin D might explain why some patients, such as the elderly, are more vulnerable to COVID-19, since they're also more likely to suffer from vitamin D deficiency. Children, on the other hand, may be less susceptible to severe cases in part because their immune system may be less likely to overreact to the virus and cause complications like a cytokine storm.
But no vitamin is a cure-all, and this is no exception. If you're already getting an adequate amount of vitamin D, from sunlight, food, or other sources, adding more won't help. In fact, getting too much vitamin D can have negative side effects.
"While I think it is important for people to know that vitamin D deficiency might play a role in mortality, we don't need to push vitamin D on everybody," Vadim Backman, professor of biomedical engineering at Northwestern University and a lead researcher in the study said in a press release. "It will not prevent a patient from contracting the virus, but it may reduce complications and prevent death in those who are infected."
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