(News release from SSM Health, Oct. 14)

Vitamin D, sometimes known as the “sunshine vitamin,” is in the limelight for its possible effect on COVID-19. Several vitamin D studies have encouraging results, but it is too early to definitively say that it can help prevent or fight the virus.

Vitamin D is historically known for supporting bone health, cell growth and the immune system. One of our primary sources is the sun, as UV rays can trigger vitamin D synthesis in the body. Questions about its benefits have even surrounded pandemics before.

“During the Spanish Flu outbreak in 1918, patients who were in an enclosed tent without sunshine fared worse than those who were able to spend regular time outside,” says SSM Health Infectious Disease physician Dr. Amanda Carlson. “Obviously, the research then was observational and conclusive evidence was lacking.”

Now, as the world puts COVID-19 under the microscope, researchers are again turning to vitamin D. One study out of Boston University found that patients who had sufficient vitamin D levels were less likely to have severe COVID-19 complications and were 51-percent less likely to die, compared to patients who had lower vitamin D levels. Another study found that adequate levels of vitamin D may actually decrease your risk of being infected by COVID-19 in the first place.

However, just like with the Spanish Flu, this research is again observational.

“These are very important studies because we don’t have a COVID-19 cure and continue to learn a lot about how to treat the virus,” says Dr. Carlson. “However, they’ve come with some scrutiny because higher levels of vitamin D are often seen in younger populations. Younger people tend to be healthier in general, which might allow their bodies to better fight COVID-19. We need a randomized study that would match variables between two groups to be able to say that vitamin D does in fact have a connection.”

In the meantime, should you start taking vitamin D supplements regularly?

“Vitamin D deficiency is very common, so many primary care providers already ask patients to take daily pills, especially during seasons when they aren’t exposed to very much sunlight,” says Dr. Carlson. “So if you start a regiment, you’ll receive all the proven benefits and any COVID-19 defense could be an added bonus.”

Vitamin D supplements are easy to find, as they are sold over the counter. Dr. Carlson adds that before taking any supplement, you should talk to your primary care provider about usage and dosage recommendations.