Table 4.

Findings of the reviewed studies

Study Citation	Patient's characteristics		Severity of disease	Outcomes	Components
	Age	Comorbidities			Component	Form	Dose	Duration
Farnoosh, et al25	50.7±14.4	Hypertension 33.3% Diabetes 25% Rheumatic disease 4.2% Cardiovascular disease 12.5% Cancer	Mild to moderate	Clinical improvement of symptoms and laboratory parameters	Melatonin	Oral	3mg*3/day	14 days
Hasan ZT, et al 26	56.3±7.3	Hypertension 53.2% Ischemic heart disease 15.8% Asthma 29.7%	Severe	thrombosis, sepsis, and mortality rate	Melatonin	Oral	10 mg	14 days
Marina Sánchez-Rico, et al 27	18–70 71–80 81+	diabetes mellitus diseases of the circulatory system diseases of the respiratory system neoplasms and diseases of the blood	NA	in-hospital all-cause mortality	Melatonin	Oral	2.61 mg
Ben Abdallah S et al 31	54.2 ± 17.3	NA	Moderate	*For inpatients: death, need for ICU admission and length of ICU and hospital stay at 30-day *For outpatients: appearance of new symptoms, the need for hospitalization, need for ICU admission, and survival status	Zinc	Oral	25 mg	15 days
Oneel Patel, et al32	59.8 ± 16.8	Hypertension Diabetes Chronic cardiovascular disease Chronic respiratory Disease Cirrhosis Hepatic Failure	Moderate to severe	In non‐ventilated patients was assessed as the level of oxygenation expressed as oxygen flow (in liters/min) required to maintain blood oxygen levels (SpO2) above 94% and the worst (lowest) PaO2/FiO2 ratio in ventilated patients	Zinc	IV	0.24 mg/kg/day	7 days
Margolin, et al33	45.2 (14.6)	Diabetes Hypertension Dyslipidemia Asthma	Mild Outpatients	the number of days required to reach a 50% reduction in symptoms	Vitamin C Zinc	Oral	*8000 mg of ascorbic acid (to be divided over 2-3 times per day) *50 mg of zinc	10 days
Majidi, et al 35	59.42± 15		Severe	Survival duration	Vitamin C	IV	500 mg	14 days
Poona Kumari, et al 36	52 ± 11		Moderate to severe	*Days to be symptom-free * Days spent in the hospital * Need for mechanical ventilation	Vitamin C	IV
Castillo ME, et al38	53.14 +/- 10.77	Lung disease Diabetes mellitus Hypertension Cardiovascular disease	Moderate to Severe	Rate of ICU admission and deaths	Vitamin D	Oral	0.532 mg 0.266 mg 0.266 mg	Day1 Day3 Day7
Igor H Murai, et al39	56.2 [14.4]		Moderate to severe	length of stay in hospital	Vitamin D	Oral	200 000 IU	1 day