The peer-reviewed study, published in the journal PLoS ONE, looked at vitamin D levels before a person contracted COVID-19 and the disease’s severity and mortality.
The latest study is among the first to look at vitamin D levels before a person contracted the virus. Researchers say this gives a more accurate assessment than when measuring vitamin D levels when the person is already being hospitalized for COVID-19, when levels may be lower due to the disease.
Researchers from Azrieli Faculty of Medicine of Bar-Ilan University and the Galilee Medical Center found that patients with vitamin D deficiency (less than 20 ng/mL) were 14 times more likely to have a severe or critical case of COVID-19, compared to those with levels of vitamin D at more than 40 ng/mL.
Amiel Dror, the lead researcher of the study, said results of the study suggest it is “advisable to maintain normal levels of vitamin D.
“This will be beneficial to those who contract the virus,” he said in a statement. “There is a clear consensus for vitamin D supplementation on a regular basis as advised by local health authorities as well as global health organizations.”
The study also found that a lower vitamin D status was more common in patients with severe or critical COVID-19, compared to those with mild to moderate COVID-19.
Researchers carried out a retrospective study, analyzing records of 1,176 patients, 253 of whom had records of a 25(OH)D level before they were infected with the CCP (Chinese Communist Party) virus, also known as the novel coronavirus.
People included in the study were aged 18 years old and above, and had PCR-confirmed COVID-19 between April 7, 2020, and Feb. 4, 2021—during Israel’s first two waves of the virus, before the emergence of the highly contagious but generally far less severe COVID-19 variant, Omicron.
Scientists observed that mortality among patients with sufficient vitamin D levels was 2.3 percent, compared to 25.6 percent in those who were in the vitamin D deficient group.
The data was adjusted for age, gender, season (summer/winter), and chronic diseases, from which researchers “found similar results across the board highlighting that low vitamin D level contributes significantly to disease severity and mortality,” according to a news release from Bar-Ilan University.
Michael Edelstein, a study co-author, said that the findings contribute to a growing body of evidence that suggest that vitamin D deficiency is a predictive risk factor associated with poorer COVID-19 clinical disease course and mortality.
“It is still unclear why certain individuals suffer severe consequences of COVID-19 infection while others don’t,” he said. “Our finding adds a new dimension to solving this puzzle.”
Amir Bashkin, an endocrinologist who participated in the study, said that maintaining normal levels of vitamin D “has an added benefit for the proper immune response to respiratory illness.”
Vitamin D also contributes to bone, heart, and brain health. Studies have suggested that low levels of vitamin D is associated with autoimmune and inflammatory diseases, cardiovascular diseases, infectious diseases, as well as diabetes and cancer.