High vitamin D levels may protect against COVID-19, especially for Black people, study finds

As people begin to soak up more of the springtime sun, the rays may offer more than just a reprieve from cabin fever.

A new study finds that COVID-19 patients, particularly Black patients, with high vitamin D levels may have a lower risk of being infected with COVID-19.

University of Chicago Medicine researchers, who published their findings in the medical journal JAMA Open Network, studied 3,000 patients who had their vitamin D levels tested within two weeks before a COVID-19 test.

“These new results tell us that having vitamin D levels above those normally considered sufficient is associated with decreased risk of testing positive for COVID-19, at least in Black individuals,” lead author of the study Dr. David Meltzer said in a press release.

Vitamin D can be produced by the body in response to skin’s exposure to sunlight, but can also be obtained through diet and supplements. Meltzer explained that people with darker skin generally have lower levels of vitamin D.

Doctors mostly recommend vitamin D levels of 30 ng/ml to be sufficient for people to be healthy. But the study found Black patients whose levels were between 30 to 40 ng/ml had a 2.6 times higher risk of testing positive for COVID-19 — compared to those with levels of 40 ng/ml.

“This supports arguments for designing clinical trials that can test whether or not vitamin D may be a viable intervention to lower the risk of the disease, especially in persons of colour,” Meltzer, who’s also chief of Hospital Medicine at UChicago Medicine, added.

Now, his team are testing how effective vitamin D supplements are at preventing COVID-19 in general.

The researchers have been examining the relationship between the likelihood of being infected and vitamin D levels for months, with this study following an earlier one that found that a vitamin D deficiency (less than 20 ng/ml) may actually raise the risk of testing positive for COVID-19.

The connection between vitamin D and COVID-19 is turning out to be a hot target for scientists.

A separate study found more than 80 per cent of those diagnosed with COVID-19 were vitamin D deficit. And another study, presented virtually at the Endocrine Society’s annual meeting this weekend, found that hospitalized COVID-19 patients with low vitamin D levels were less likely to die or require ventilators if they were given supplements of the compound.

Although Metzer said a lot of research has been done on vitamin D’s impact on bone health, there’s only been some evidence that vitamin D might improve immune function and decrease inflammation. He said his latest study shows that past studies may not have used enough vitamin D to truly examine its impact on the immune system.

But Meltzer cautions that this was an observational study, meaning it didn’t determine a direct cause and effect between vitamin D and contracting COVID-19.

“We can see that there’s an association between vitamin D levels and likelihood of a COVID-19 diagnosis, but we don’t know exactly why that is, or whether these results are due to the vitamin D directly or other related biological factors.”

This content was republished with permission from CNN.

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