Table 1.
Description of eligible studies on clinical trials on the effects of zinc and selenium against COVID-19.
| Study | Trial type and duration |
Population | Population characteristics | Location | Interventions | Conclusions of the study |
|---|---|---|---|---|---|---|
| Abd-Elsalam 2021 [49] | RCT 23 June 2020–23 August 2020 28 days |
Confirmed diagnosis of COVID-19 infection N = 191 |
Female: 44 IG group-31 CG; Male: 52 IG-64 CG Excluded: patients with hypokalemia or hypomagnesemia, porphyria, neutrophilia, myasthenia gravis, maculopathy or changes in the visual field, heart failure, prolonged QT interval in ECG, liver cirrhosis, psoriasis, epilepsy, anemia from pyruvate kinase and G6PD deficiencies, chronic kidney disease, and pregnant or lactating females |
Egypt | Combination of: -CQ/HCQ -220 mg of zinc sulfate twice daily (50 mg of elemental zinc twice daily) |
Zinc supplements did not modify the clinical efficacy of HCQ: recovery after 28 days and death fate were 79.2% and 5.2% in intervention group respectively, and 77.9% and 5.3% in control group respectively. |
| Margolin 2021 [50] | Non-randomized clinical trial March 2020–July 2020 20 weeks |
Healthy exposed population N = 113 |
53 IG-60 CG Female/male: approximately 60/40% Excluded: oxygen saturation <94%, afebrile temperature |
United States (Ohio) | Combination of: -Zinc 25 mg once a day -Vitamin C -Vitamine D3 -Vitamine E -l-lysine -Quercetin -Quina™ |
15% were diagnosed with SARS-CoV-2 infection in the control group after 20 weeks, 0% in intervention group. |
| Patel 2021 [51] | Phase IIa pilot double‐blind RCT From May 2020 28 days |
COVID‐19 confirmed hospitalized adults with oxygen saturation (SpO2) of ≤94% N = 33 |
Female: 4 IG-8 CG Male: 11 IG-10 CG Excluded: age<18, pregnant, lactating female, allergy to zinc, severe hepatic impairment, history of organ transplant which requires immunosuppressive treatment which can interfere with kidney function, HIV infection, patient required cardiopulmonary resuscitation, imminent or inevitable death, eGFR<60 mL/min/1.73 m2 or patient requiring dialysis, haemochromatosis |
Australia | -0.5 mg/kg/day of zinc chloride (0.24 mg/kg/day elemental zinc) by intravenous infusion | The primary outcome in non-ventilated patients was oxygen flow required to maintain blood oxygen levels above 94%. Did not reach its target enrollment. Same clinical results in the two groups. HDIVZn increased serum zinc levels above the deficiency cutoff of 10.7 μmol/L in the intervention arm. |
| Thomas 2021 [52] | RCT 27 April 2020–14 October 2020 10 days |
Diagnosis of SARS-CoV-2 infection confirmed with a polymerase chain reaction assay N = 214 |
Female: 37 only zinc IG-31 CG Male: 21 only zinc IG-19 CG Excluded: hospitalized, resided outside of Ohio or Florida, pregnant, actively lactating, had advanced chronic kidney disease, liver disease awaiting transplantation, or history of calcium oxalate kidney stones |
United States (Ohio and Florida) | Separately: -50 mg of zinc gluconate once a day (7 mg of elemental zinc once a day [79]) -Ascorbic acid -Combination of both treatments |
Study was stopped. Treatment had no effect on SARS-CoV-2 symptoms. 50% reduction in symptoms occurred in a mean of 6.7 days in standard care group and 5.9 days in zinc only group. |
Abbreviations: CG, control group; CQ, chloroquine; eGFR, estimated glomerular filtration rate; HCQ, hydroxychloroquine; HDIVZn, high‐dose intravenous zinc; IG, intervention group; RCT, randomized controlled trial.