New Research Suggests Importance Of Vitamin D In Protecting Against Severe Covid-19

A newly published study by a team of researchers from the Azrieli Faculty of Medicine of Bar-Ilan University in Safed, Israel and the Galilee Medical Center in Nahariya, Israel shows a link between vitamin D deficiency and severity of disease from Covid-19 infection.

Published in the journal PLOS ONE, the research team looked at vitamin D levels in 1,176 patients hospitalized with positive PCR test result between April 2020 and February 2021 at the Galilee Medical Center. The vitamin D levels were based on testing that had been conducted prior to the hospitalization “either as part of a routine blood workup or following a clinical suspicion for vitamin D deficiency.” Those lab results had occurred anywhere from 14 to 730 days before the positive Covid tests.

Patients with a vitamin D deficiency (defined as less than 20 ng/mL) were 14 times more likely to have a severe or critical case of COVID than those with more than 40 ng/mL. In addition, the mortality rate for patients who had sufficient vitamin D levels was 2.3%, compared to 25.6% for patients in the vitamin D deficient group.

Those striking differences were found even after the researchers controlled for the patients’ age, gender and history of chronic diseases. And because the vitamin D levels were assessed prior to infection, the study avoids the problem that vitamin depletion might have been due to the virus itself.

Vitamin D has long been recognized for its many health benefits such as promoting healthy bones and teeth, supporting the immune system, and lowering cardiovascular health risks. And during the pandemic, physicians have been advising their patients to take vitamin D because they thought it could help boost their immune systems, despite little direct empirical evidence to back up that advice. (I know because my physician gave me just such advice.)

Quoted in The Times of Israel, Dr. Amiel Dror, a physician and Bar Ilan researcher who led the research team, said, “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.”

The Israeli study was conducted pre-Omicron, but Dror believes that vitamin D effectiveness would still be found for Covid variants. “What we’re seeing when vitamin D helps people with COVID infections is a result of its effectiveness in bolstering the immune systems to deal with viral pathogens that attack the respiratory system,” he added.

The authors concluded their published report with the following: “Our study contributes to a continually evolving body of evidence that suggests a patient’s history of vitamin D deficiency is a predictive risk factor associated with poorer COVID-19 clinical disease course and mortality.”