[ad_1]
People who are deficient in vitamin D may have a higher risk of contracting the new coronavirus than those with sufficient levels, according to the results of a new retrospective study from Illinois.
People with untreated vitamin D deficiency were nearly twice as likely to test positive for COVID-19 compared to their peers with adequate vitamin D levels.
“These findings appear to support a role for vitamin D status in COVID-19 risk,” say the authors in the study, published online Sept. 3 in JAMA network open.
“Vitamin D is important for immune system function and vitamin D supplementation has previously been shown to reduce the risk of viral respiratory tract infections. Our statistical analysis suggests that this may be true for COVID-19 infection.” said lead author David Meltzer. , MD, PhD, chief of hospital medicine at Chicago Medical University, Illinois, in a news release from their institution.
Important for immune function
Meltzer and her colleagues studied 489 University of Chicago Medicine patients (average age 49, 75% female) whose vitamin D levels were determined in the 2 months prior to being tested for COVID-19.
Vitamin D deficiency was defined as <20 ng / ml of 25-hydroxycholecalciferol or <18 pg / ml of 1,25-dihydroxycholecalciferol.
Vitamin D status was classified as probably poor for 124 participants (25%), probably sufficient for 287 (59%), and unclear for 78 (16%).
A total of 71 participants (15%) tested positive for COVID-19.
In a multivariate analysis, a positive COVID-19 test was significantly more likely in those with probable vitamin D deficiency than in those with probably sufficient levels of vitamin D at the time of the COVID-19 test (relative risk [RR]1.77; 95% CI, 1.12-2.81; P = .02).
The estimated mean rate of COVID-19 in the deficient group was 21.6% compared to 12.2% in the sufficient group.
Positive COVID-19 testing was also associated with increasing age up to 50 years (RR, 1.06; P = .02) and a race other than white (RR, 2.54; P = .009)
Protective effect of the treatment?
The findings also raise the possibility that treatment for vitamin D deficiency may reduce the risk of COVID-19, the researchers say.
Patients with deficient levels of vitamin D who received increased vitamin D treatment did not appear to be at increased risk for COVID-19.
This suggests a “protective effect of treatment, but the confidence intervals in the estimated rates for these groups are too wide to exclude the possibility of no treatment effect,” Meltzer and colleagues note.
“If vitamin D reduces the incidence of COVID-19, it is tempting to consider whether it could reduce the transmission of COVID-19,” they hypothesize.
Because vitamin D strengthens innate immunity, it could be expected to decrease COVID-19 infection and transmission. Vitamin D also affects zinc metabolism, which slows the replication of coronaviruses.
As previously reported by Medscape Medical News, a recent study from Israel suggested that low plasma vitamin D levels are an independent risk factor for COVID-19 infection and hospitalization.
In that study, participants positive for COVID-19 were 50% more likely to have low vitamin D levels compared to normals in a multivariate analysis that controlled for other confounders.
Half of Americans are deficient in vitamin D, with much higher rates in African Americans, Hispanics, and people who live in areas like Chicago where it is difficult to get enough sun exposure in winter.
“Understanding whether treating vitamin D deficiency changes the risk of COVID-19 could be of great importance locally, nationally, and globally,” said Meltzer. “Vitamin D is cheap, generally very safe to take, and can be scaled widely.”
Meltzer and colleagues say that randomized clinical trials are now needed to see if population-wide interventions and interventions among groups at increased risk of vitamin D deficiency and COVID-19 could reduce COVID-19 cases.
The study was supported by the Learning Health Care System Core of the University of Chicago / Rush University Institute for Translational Medicine (ITM) Clinical and Translational Science Award and the African American Cardiovascular Pharmacogenetics Consortium. The authors have declared no relevant conflicts of interest.
JAMA Netw Open. Published on September 3, 2020. Full text
For more news on diabetes and endocrinology, follow us on Twitter and Facebook.
[ad_2]
