Foods rich in vitamin D.
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 in the University of Chicago Medicine has found that when it comes to COVID-19, having vitamin D levels above those traditionally considered sufficient can reduce the risk of infection, especially for black people.
The study, published today (March 19, 2021) in JAMA Open Network, retrospectively examined the relationship between vitamin D levels and the probability of a positive test for COVID-19. Although levels of 30 ng / ml or more are generally considered “sufficient”, the authors found that black individuals who had levels of 30 to 40 ng / ml had a 2.64-fold higher risk of a positive test for COVID-19 than than people with levels of 40 ng / ml or higher. Statistically significant associations between vitamin D levels and the risk of COVID-19 were not found in white people. The study analyzed data from more than 3,000 UChicago Medicine patients who had their vitamin D levels tested 14 days before a COVID-19 test.
The research team is now recruiting participants for two separate clinical trials that test the effectiveness of vitamin D supplements in preventing COVID-19.
This research is an expansion of a previous study that shows that a vitamin D deficiency (less than 20 ng / ml) may increase the risk of a positive test for COVID-19. In the current study, these results were later confirmed, finding that individuals with vitamin D deficiency had a 7.2% chance of positive testing for the virus. A separate study recently found that more than 80% of patients diagnosed with COVID-19 were deficient in vitamin D.
“These new results tell us that having vitamin D levels above those normally considered sufficient is associated with a decreased risk of a positive test for COVID-19, at least in black individuals,” said David Meltzer, MD, PhD, Chief of Medicine Hospital in UChicago Medicina and main author of the study. “This supports the arguments for the design of clinical trials that can test whether vitamin D may or may not be a viable intervention to reduce the risk of the disease, especially in people of color.”
Meltzer was inspired to investigate this topic after seeing an article in early 2020 that found that people with vitamin D deficiency who had been randomly assigned to receive vitamin D supplementation had much lower rates of viral respiratory infections compared to those who received no supplementation. He decided to examine the data collected at UChicago Medicine at COVID-19 to determine the role that vitamin D levels may be playing.
“There is a lot of literature on vitamin D. Most of it focuses on bone health, which is where the current standards for sufficient levels of vitamin D come from,” explained Meltzer. “But there is also evidence that vitamin D can improve immune function and decrease inflammation. So far, the data has been relatively inconclusive. Based on these results, we think that previous studies may have given doses too low to have a significant effect on the immune system, even if they were sufficient for bone health. It may be that different levels of vitamin D are suitable for different functions. “
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; about half of the world population has levels below 30 ng / ml. “Lifeguards, surfers, this is the type of person who tends to have more than enough levels of vitamin D,” he said. “Most people who live in Chicago in the winter will have levels well below that.”
Although vitamin D supplements are relatively safe, excessive consumption of vitamin D supplements is associated with hypercalcemia, a condition in which calcium accumulates in the bloodstream and causes nausea, vomiting, weakness and frequent urination. If left unchecked, it can cause even more pain in the bones and kidney stones.
“Currently, the recommended vitamin D intake for adults is 600 to 800 international units (IU) per day,” said Meltzer. “The National Academy of Medicine said that taking up to 4,000 IU per day is safe for the vast majority of people, and the risk of hypercalcemia increases at levels above 10,000 IU per day.”
One of the challenges of this study is that it is currently difficult to determine exactly how vitamin D may be supporting immune function. “This is an observational study,” said Meltzer. “We can see that there is an association between vitamin D levels and the likelihood of a diagnosis of COVID-19, but we don’t know exactly why that is, or whether these results are directly due to vitamin D or other related biological factors” .
Encouraged by the evidence that people with vitamin D deficiency are more likely to test positive for COVID-19 and have significant symptoms, a team from the University of Chicago and Rush University is conducting two studies on whether to take a daily vitamin D supplement. can help prevent COVID-19 or lessen the severity of your symptoms.
Individuals who want to know more about the study and determine their eligibility can visit https: /
Reference: “Association of vitamin D levels, race / ethnicity and clinical characteristics with results from the COVID-19 test” by Thomas J. Best, Hui Zhang, Tamara Vokes, Vineet M. Arora and Julian Solway, March 19, 2021, Open JAMA network.
DOI: 10.1001 / jamanetworkopen / 2021.4117