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. 2020 Aug 1;9(8):1036. doi: 10.3390/foods9081036

Table 1.

List of the current clinical trials related to food (micronutrients, foods/diets, and other supplements) used for the prevention/treatment of COVID-19 as of 24 May 2020 [15]. A brief description reporting the trials’ aims, enrolment, and interventions is also reported.

№. Treatment Brief Trial Description ⱡ ,$,*
Micronutrients
1 Vitamin C
Zinc gluconate		 Aim Reduce symptom duration
Enrolment 18 years and older, COVID-19-positive, 520 participants
Intervention
  • -

    IG 1: vitamin C (8000 mg/day)

  • -

    IG 2: zinc gluconate (50 mg/day)

  • -

    IG 3: vitamin C (8000 mg/day) and zinc gluconate (50 mg/day)

  • -

    CG: standard care

Duration: 10 days
2 Vitamin C Aim Reduce mortality and secondary symptoms
Enrolment All ages, COVID-19-positive, 500 participants
Intervention
  • -

    IG: intravenous vitamin C (10 g/not specified)

Duration: not specified
3 Zinc gluconate
Vitamin D3		 Aim Reduce inflammatory reaction, which worsens acute respiratory distress syndrome
Enrolment 60 years and older, COVID-19-positive, 3140 participants ¥
Intervention
  • -

    IG: zinc gluconate (30 mg/day) and vitamin D3 (2000 IU (International Units)/day)

  • -

    CG: standard care

Duration: 2 months
4 Vitamin D Aim Improve hard endpoints related to COVID-19 deleterious consequences
Enrolment 40 years to 70 years, COVID-19-positive, 200 participants
Intervention
  • -

    IG: vitamin D (25,000 UI/day)

  • -

    CG: standard care

Duration: not specified
5 Hydroxychloroquine
Vitamin C
Vitamin D
Zinc		 Aim Determine whether the combined therapy prevents COVID-19 symptoms ⴕ
Enrolment 18 years and older, FM, COVID-19-negative: high-risk individuals, 600 participants
Intervention
  • -

    IG: hydroxychloroquine, vitamin C, vitamin D, zinc (not specified)

Duration: not specified
6 Hydroxychloroquine
Azithromycin
Vitamin C
Vitamin D
Zinc		 Aim Determine whether the combined therapy can treat COVID-19 infection
Enrolment 18 years and older, COVID-19-positive, 600 participants
Intervention
  • -

    IG: hydroxychloroquine, azithromycin, vitamin C, vitamin D, zinc (not specified)

Duration: 24 weeks
7 Vitamin C Aim Increase ventilator-free days, acute-inflammation-free days and organ-failure-free days
Enrolment 18 years and older, FM, COVID-19-positive, 200 participants
Intervention
  • -

    IG: intravenous vitamin C (100 mg/kg/8 hours)

  • -

    CG: standard care

Duration: 3 days
8 Vitamin D3 Aim Improve the prognosis of older patients
Enrolment 70 years and older, FM, COVID-19-positive, 260 participants ¥
Intervention
  • -

    IG: vitamin D3 (400,000 IU/day)

  • -

    CG: standard dose of vitamin D3 (50,000 IU/day)

Duration: not specified
9 Vitamin C Aim Improve the prognosis of patients
Enrolment 18 years and older, COVID-19-positive, 140 participants
Intervention
  • -

    IG: intravenous vitamin C (24 g/day)

  • -

    CG: standard care

Duration: 7 days
10 Vitamin C Aim Reduce the risk of respiratory failure requiring mechanical ventilation
Enrolment 18 years to 99 years, FM, COVID-19-positive, 20 participants
Intervention
  • -

    IG 1: intravenous vitamin C (50 mg/kg/6 h) (mild deoxygenation)

  • -

    IG 2: intravenous vitamin C (50 mg/kg/6 h) (severe deoxygenation)

Duration: 4 days
11 Vitamin C
Active comparator treatment (hydroxychloroquine, azithromycin, zinc citrate, vitamin D3 and vitamin B12)		 Aim Prevent COVID-19 progression
Enrolment 18 years and older, COVID-19-positive, 200 participants
Intervention
  • -

    IG: vitamin C (200 mg/kg/day on day 1, 400 mg/kg/day from day 2) and active comparator treatment (hydroxychloroquine, azithromycin, zinc citrate, vitamin D3 and vitamin B12)

  • -

    CG: active comparator treatment

Duration: 7 days
12 Vitamin D2
Vitamin D3		 Aim Determine the efficacy of vitamin D in patients
Enrolment 17 years and older, FM, COVID-19-positive, 64 participants
Intervention
  • -

    IG 1: vitamin D2 (4 doses of 50000 IU in 3 weeks)

  • -

    IG 2: vitamin D3 (1000 IU/day)

Duration: 3 weeks
13 Calcifediol Aim Study the preventive and therapeutic effects of oral calcifediol ⴕ
Enrolment 18 years to 75 years, COVID-19-negative and at high risk of acquiring COVID-19, or at risk for its morbidity and mortality, 1500 participants
Intervention
  • -

    IG: oral calcifediol (25 µg/day)

  • -

    CG: standard care

Duration: 2 months
14 Calcifediol Aim Reduce the development of COVID-19 and the worsening of the various syndrome phases
Enrolment 18 years to 90 years, COVID-19-positive, 1008 participants
Intervention
  • -

    IG: oral calcifediol (266 µg/12 h on day 1, 266 µg/day on days 3, 7, 14, 21, 28)

  • -

    CG: standard care

Duration: 28 days
15 Vitamin C Aim Evaluate the safety and efficacy of ascorbic acid infusions in COVID-19 treatment
Enrolment 18 years and older, COVID-19-positive, 66 participants
Intervention
  • -

    IG: vitamin C infusion (0.3 g/kg on day 0, 0.6 g/kg on day 1, 0.9 g/kg on days 3–5)

  • -

    CG: standard care

Duration: 6 days
16 Aspirin
Vitamin D		 Aim Test the hypothesis that treatment with aspirin and vitamin D in COVID-19 can mitigate the prothrombotic state and reduce hospitalization rates
Enrolment 18 years and older, FM, COVID-19-positive, 1080 participants
Intervention
  • -

    IG 1: aspirin (81 mg/day)

  • -

    IG 2: aspirin (81 mg/day) and vitamin D (50000 IU/week)

  • -

    CG: standard care

Duration: 2 weeks
Foods/diets
17 Natural honey Aim Study the efficacy of natural honey in patient treatment
Enrolment 5 years to 75 years, COVID-19-positive, 1000 participants
Intervention
  • -

    IG: natural honey (1 g/kg/day)

  • -

    CG: standard care

Duration: 14 days
18 Natural honey
Black cumin		 Aim Reduce COVID-19 symptoms
Enrolment 18 years and older, COVID-19-positive, 30 participants
Intervention
  • -

    IG: natural honey and black cumin (1 g/kg/day)

  • -

    CG: standard care

Duration: 14 days
19 Ketogenic diet Aim Improve gas exchange, reduce inflammation and duration of mechanical ventilation
Enrolment 18 years to 80 years, COVID-19-positive, 15 participants
Intervention
  • -

    IG: ketogenic diet

  • -

    CG: standard care

Duration: 2 days
Other supplements
20 Nutritional supplement enriched in eicosapentaenoic acid, gamma linolenic acid, and antioxidants Aim Reduce COVID-19 severity with more preservation of the nutritional status
Enrolment 18 years to 65 years, COVID-19-positive, 30 participants
Intervention
  • -

    IG: oral nutrition supplement (ONS) enriched in eicosapentaenoic acid, gamma linolenic acid, and antioxidants

  • -

    CG: isocaloric/isonutrigenous ONS

Duration: 14 days
21 Resistant potato starch
Nonresistant corn starch		 Aim Determine the efficacy of resistant potato starch in reducing the need for hospitalization
Enrolment 19 years and older, COVID-19-positive, 1300 participants
Intervention
  • -

    IG: resistant potato starch (20 g/12 h)

  • -

    CG: nonresistant corn starch (20 g/12 h)

Duration: 14 days
22 Gum arabic
Pectin		 Aim Study the efficacy of gum arabic as an immunomodulator and anti-inflammatory agent
Enrolment 5 years to 90 years, COVID-19-positive, 110 participants
Intervention
  • -

    IG: gum arabic (30 g/day)

  • -

    CG: pectin (1 g/day)

Duration: 4 weeks for IG and 12 weeks for CG
23 Quercetin Aim Evaluate the possible role of quercetin on prophylaxis and treatment of COVID-19 ⴕ
Enrolment 18 years and older, COVID-19-negative and -positive, 50 participants
Intervention
  • -

    IG 1: quercetin (1000 mg/day in COVID-19 patients)

  • -

    IG 2: quercetin (500 mg/day in NO COVID-19 patients)

  • -

    CG: no intervention (in NO COVID-19 patients)

Duration: not specified

ⱡ IG = intervention group; CG = control group. ¥ The trial is being carried out on elderly participants. ⴕ Studies with prevention aim. $: All studies are ongoing. * Both sexes were recruited.