Low vitamin D levels are increasingly being linked to an increased risk of COVID-19 infection and death.
One study, recently published in PLOS ONE, is one of the first to look at vitamin D levels before COVID-19 infection. The paper allows for a more accurate measurement than would be possible during hospitalization, when levels may be lower due to the viral disease.
The records of 1,176 patients admitted to the Galilee Medical Center (GMC) with positive PCR testing between April 2020 and February 2021 were checked for vitamin D levels measured two weeks to two years prior to infection.
Patients with vitamin D insufficiency (less than 20 ng/mL) were 14 times more likely than those with more than 40 ng/mL to have a severe or critical case of COVID.
Surprisingly, patients with adequate vitamin D levels had a death rate of 2.3 percent, compared to 25.6 percent in the vitamin D deficient group.
The researchers adjusted for age, gender, season (summer/winter), and chronic conditions and found identical results across the board, indicating that low vitamin D levels have a substantial role in disease severity and mortality.
"Our results suggest that it is advisable to maintain normal levels of vitamin D. This will be beneficial to those who contract the virus," Dr. Amiel Dror of the Galilee Medical Center and Azrieli Faculty of Medicine of Bar-Ilan University, who led the study said.
"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."
Although the Israeli study was conducted prior to Omicron, Dror feels that vitamin D effectiveness would still be seen in Covid variants.
Although vitamin D is well known for its role in bone health, low levels of the supplement have been linked to a variety of autoimmune, cardiovascular, and infectious illnesses. Early in the pandemic, health officials encouraged patients to take vitamin D, which helps promote immune response and may protect against COVID-19.
A torrent of spurious claims about natural coronavirus cures, including a suggestion that people had immunized themselves with lemons and baking powder, has led some to be wary about vitamin claims to fight off the virus.
The authors concluded their paper by saying that the study adds to a growing body of evidence suggesting that a patient's history of vitamin D insufficiency is a predicted risk factor for a worse COVID-19 clinical disease course and mortality.
Researchers will now examine whether these findings are repeatable, and if so, how vitamin D sufficiency can be best ensured in clinical practice.
