Israeli scientists said they found "striking" differences in the chances of getting seriously ill from COVID-19 when they compared patients who had sufficient vitamin D levels prior to contracting the disease, with those who didn't.
A study published Thursday in research journal PLOS One found that about half of people who were vitamin D deficient before getting COVID-19 developed severe illness, compared to less than 10 percent of people who had sufficient levels of the vitamin in their blood.
We know vitamin D is vital for bone health, but its role in protecting against severe COVID-19 is less-well established.
The latest research was the first to examine vitamin D levels in individuals prior to them contracting COVID-19, the study authors said.
Dr. Amiel Dror, a study author and physician at the Galilee Medical Center, said of the findings: "We found it remarkable, and striking, to see the difference in the chances of becoming a severe patient when you are lacking in vitamin D compared to when you're not," per the Times of Israel.
The findings come from 253 people admitted to Galilee Medical Center in Nahariya, Israel between 7 April 2020 and 4 February 2021 – a period before the highly-infectious Omicron variant emerged.
"This is equally relevant for Omicron as it was for previous variants," Dror said.
The research doesn't prove vitamin D protects against COVID-19 and isn't a green light to avoid vaccines and take vitamins instead. Vaccines cut the risk of Omicron hospitalization, particularly after a booster, by up to 90 percent, according to the UK Health Security Agency.
Most vitamin D comes from direct sunlight on the skin. It's also found in foods such as fatty fish, mushrooms, and egg yolks as well as supplements.
Vitamin D levels of more than 20 nanograms per milliliter are considered sufficient for most people, according to the Centers for Disease Control and Prevention – which is the benchmark used by the researchers from Bar-Ilan University and Galilee Medical Center.
It wasn't clear – even from those studies with results showing a positive correlation between low vitamin D levels and severe COVID-19 – if depleted vitamin D came before or after people got sick, the Israeli researchers said.
Despite the new Israel data, we still don't know if low vitamin D levels cause people with COVID-19 to develop serious disease.
Underlying conditions that reduce vitamin D can also make people more vulnerable to severe COVID-19, for example.
The Israeli researchers cautioned vitamin D was "one piece of the complex puzzle" underlying severe COVID-19, in addition to comorbidities, genetic predisposition, dietary habits, and geographic factors.
"Our study warrants further studies investigating if and when vitamin D supplementation among vitamin D deficient individuals in the community impacts the outcome of an eventual COVID-19 episode," they said.
This article was originally published by Business Insider.
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