In a retrospective study of individuals tested for COVID-19, vitamin D levels above those traditionally considered sufficient were associated with a lower risk of COVID-19.
A new research study at the University of Chicago Medicine has found that when it comes to COVID-19, having vitamin D levels above those traditionally considered sufficient may lower the risk of infection, especially for Black people.
The study, published March 19 in JAMA Open Network, examined the relationship between vitamin D levels and likelihood of testing positive for COVID-19. The authors found that Black individuals who had higher levels of vitamin D were significantly less likely to test positive for COVID-19, compared to those people who had merely “sufficient” levels of vitamin D.
“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,” said David Meltzer, MD PhD, Chief of Hospital Medicine at UChicago Medicine and lead author of the study. “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 color.”
Vitamin D can be obtained through diet or supplements, or produced by the body in response to exposure of the skin to sunlight. Meltzer noted that most individuals, especially people with darker skin, have lower levels of vitamin D; roughly half of the world’s population has levels considered insufficient. “Lifeguards, surfers, those are the kinds of folks who tend to have more than sufficient vitamin D levels,” he said. “Most folks living in Chicago in the winter are going to have levels that are well below that.”
While vitamin D supplements are relatively safe to take, excessive consumption of vitamin D supplements is associated with hypercalcemia, a condition in which calcium builds up in the blood stream. If left unchecked, it can lead to bone pain and kidney stones.
Prompted by the evidence that people with vitamin D deficiency are more likely to test positive for COVID-19 and experience significant symptoms, a team at the University of Chicago and Rush University is conducting two studies to learn whether taking a daily vitamin D supplement can help prevent COVID-19 or decrease the severity of its symptoms. Individuals who would like to learn more about the study and determine their eligibility can visit https://chess.uchicago.edu/vitamind/.