Abstract #52 Table 1

Studies evaluating the association between vitamin D level and COVID-19 disease severity

Author, year, and locationControls: number (N) and mean or median age (yrs)Subjects: number (N) and mean or median age (yrs)Serum 25(OH)D concentration in controls vs. subjects, p-valueOutcome based on comorbidities and vitamin D levels, p-value
Radujkovic, 2020, Germany Controls: COVID-19 outpatients, N=92, Median age=56 Subjects: COVID-19 inpatients, N=93, Median age=63 Median: 18.6 vs. 14.6 ng/mL, p=0.001 Adjusted by age, gender, and comorbidities, VDD (<12 ng/mL) was associated with invasive mechanical ventilation and death (HR 6.12 and 14.73, respectively. p<0.001 for both).
Luo, 2020, China Controls: Non-severe COVID-19, N=261, Median age=54.0 Subjects: Severe COVID-19, N=74, Median age=62.5 Median: 11.0 vs. 9.24 ng/mL, p<0.0001 Adjusted by sex, age, comorbidities, BMI, smoking status, and vitamin D status, VDD (<12 mg/L) was associated with COVID-19 severity (OR 2.72, 95% CI 1.23–6.01, p=0.014), but VDD was not associated with mortality (p=1.0).
Karahan, 2021, Turkey Controls: Moderate COVID-19, N=47, Mean age=56.1 Subjects: Severe-critical COVID-19, N=102, Mean age=67.0 Median: 26.3 vs. 10.1 ng/mL, p<0.001 25(OH)D levels significantly predictive of in-hospital mortality (multivariate analysis: OR 0.927, 95%CI 0.875–0.982, p=0.01).
Jain, 2020, India Controls: Asymptomatic COVID-19, N=91, Mean age=42.34 Subjects: Severely ill COVID-19, N=63, Mean age=51.41 Mean: 27.89 vs. 14.35 ng/mL, p=0.0001 Fatality rate for VDD (<20 ng/mL) higher than that for normal 25(OH)D (21.1% vs. 31.1%, p-value NR).
Macaya, 2020, Spain Controls: Non-severe COVID-19, N=49, Median age=63 Subjects: Severe COVID-19, N=31, Median age=75 Median: 19 vs. 13 ng/mL, p=0.145 Adjusted by age, gender, obesity, cardiac disease, and CKD, VDD (<20 ng/mL) did not significantly predict higher risk of developing severe COVID-19 (OR 3.2, 95% CI 0.9–11.4, p=0.07).
Ye, 2020, China Controls: Mild/moderate COVID-19, N=50, Median age=39 Subjects: Severe/critical COVID-19, N=10, Median age=65 Median: 22.64 vs. 15.28 ng/mL, p<0.05 Multivariate analysis including VDD, age, sex, renal failure, diabetes, and HTN: Statistically significant association between VDD (<20 ng/mL) and severe/critical COVID-19 disease (OR 15.18, 95% CI 1.23–187.45).
Kerget, 2020, Turkey Controls: COVID-19 without ARDS, N=53, Mean age=38.3 Subjects: COVID-19 with ARDS, N=35, Mean age=67.9 Mean: 21.8 vs. 16.8 ng/mL, p=0.102 NR
Campi, 2021, Italy Controls: Severely symptomatic COVID-19 hospital ward admits, N=49, Mean age=68.82 Subjects: Severely symptomatic COVID-19 ICU admits, N=54, Mean age=63.67 Mean: 22.4 vs. 14.4 ng/mL, p=0.0003 25(OH)D levels inversely correlated with subsequent need for ICU admission in severely symptomatic patients (RR 0.989, 95%CI 0.981–0.997, p=0.011), and also inversely correlated with in-hospital mortality (p=0.002).
  • Units for vitamin D levels in two studies (Luo et al. and Ye et al.), originally reported in nmol/L, were converted to ng/mL in order to achieve consistency in the units across all studies. 25(OH)D=25-hydroxyvitamin D, VDD=Vitamin D Deficiency, HR=Hazard Ratio, OR=Odds Ratio, RR=Relative Risk, NR=Not Reported