Association of vitamin D deficiency with COVID-19 severity and mortality in Iranian people: a prospective observational study

Abstract

Background: As the coronavirus disease 2019 (COVID-19) pandemic continues to escalate, it is important to identify the prognostic factors related to increased mortality and disease severity. To assess the possible associations of vitamin D level with disease severity and survival, we studied 248 hospitalized COVID-19 patients in a single center in a prospective observational study from October 2020 to May 2021 in Tehran, Iran. Methods: Patients who had a record of their 25-hydroxyvitamin D level measured in the previous year before testing positive with COVID-19 were included. Serum 25-hydroxyvitamin D level was measured upon admission in COVID-19 patients. The associations between clinical outcomes of patients and 25-hydroxyvitamin D level were assessed by adjusting for potential confounders and estimating a multivariate logistic regression model. Results: The median (interquartile range) age of patients was 60 years (44–74 years), and 53% were male. The median serum 25-hydroxyvitamin D level prior to admission decreased with increasing COVID-19 severity (P=0.009). Similar findings were obtained when comparing median serum 25-hydroxyvitamin D on admission between moderate and severe patients (P=0.014). A univariate logistic regression model showed that vitamin D deficiency prior to COVID-19 was associated with a significant increase in the odds of mortality (odds ratio, 2.01; P=0.041). The Multivariate Cox model showed that vitamin D deficiency on admission was associated with a significant increase in risk for mortality (hazard ratio, 2.35; P=0.019).Conclusions: Based on our results, it is likely that deficient vitamin D status is associated with increased mortality in COVID-19 patients. Thus, evaluating vitamin D level in COVID-19 patients is warranted.

Risk Factors Associated with Severity and Death from COVID-19 in Iran: A Systematic Review and Meta-Analysis Study

“…After deleting duplicates, we identified 2463 studies from four databases and then screened articles by title and full text according to the study's objectives. Finally, 69 studies were included in the meta-analysis (Figure 1), of which 62 studies had assessed risk factors for death from COVID 28–89 ); 13 studies determined risk factors for severity (( 41,50,53–55,65,…”

“…After deleting duplicates, we identified 2463 studies from four databases and then screened articles by title and full text according to the study's objectives. Finally, 69 studies were included in the meta-analysis (Figure 1), of which 62 studies had assessed risk factors for death from COVID ); 13 studies determined risk factors for severity (( 41,50,[53][54][55]65,[90][91][92][93][94][95][96] ), out of which six studies reported both outcomes ( (35,44,(47)(48)(49)59)). Out of 69 studies, 33 were cohort studies, eight were case-control studies, and 28 were cross-sectional studies.…”

Association of Vitamin D levels on the Clinical Outcomes of Patients Hospitalized for COVID-19 in a Tertiary Hospital

“…8 According to some studies, serum concentrations of 25(OH)D were inversely associated with pro-inflammatory cytokines, IL-6, CRP and the risk of pneumonia, acute respiratory distress syndrome (ARDS), diabetes and heart failure. 18,19 Biomarkers have been used for confirming and classifying disease severity in COVID-19 and according to some investigators, CRP was elevated in 60.7% of patients, PCT in 5.5%, and LDH in 41% of patients. 19 Patients with severe COVID-19 have a higher incidence of elevated CRP than those with a mild form of disease.…”

“…19 Another study showed findings to the contrary, that ferritin levels could predict severe disease and mortality. 18 A small retrospective study revealed that ferritin was the last parameter to return to normal making it a marker of severity and less useful for monitoring the course of disease. 24 In our investigation, the insignificant baseline levels of ferritin, LDH and procalcitonin may reflect an earlier course of their disease, while the insignificant decrease in markers from the initial results could be due to coexisting infections or comorbidities and that other repeated levels of inflammatory parameters (between baseline and final values) were not taken into account during the course of their hospitalization.…”

The close association of micronutrients with COVID-19

“…This may be because micronutrients can participate in regulating the immune response in the body, and their deficiency will cause immune imbalance in the body, and then induce various diseases [ 9 , 10 ]. It has been reported that vitamin D insufficiency was closely related to the risk and severity of COVID-19 infection [ [11] , [12] , [13] , [14] , [15] , [16] ]. However, whether other micronutrients have an impact on COVID-19 infection is largely unknown.…”