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. 2024 May 9;5(5):CD014914.
doi: 10.1002/14651858.CD014914.pub2.

Zinc for prevention and treatment of the common cold

Daryl Nault  1 , Taryn A Machingo  2 , Andrea G Shipper  3 , Daniel A Antiporta  4 , Candyce Hamel  5 , Sahar Nourouzpour  6 , Menelaos Konstantinidis  7   8 , Erica Phillips  9 , Elizabeth A Lipski  1 , L Susan Wieland  10
Affiliations

Zinc for prevention and treatment of the common cold

Daryl Nault et al. Cochrane Database Syst Rev. .

Abstract

Background: The common cold is an acute, self-limiting viral respiratory illness. Symptoms include nasal congestion and mucus discharge, sneezing, sore throat, cough, and general malaise. Given the frequency of colds, they are a public health burden and a significant cause of lost work productivity and school absenteeism. There are no established interventions to prevent colds or shorten their duration. However, zinc supplements are commonly recommended and taken for this purpose.

Objectives: To assess the effectiveness and safety of zinc for the prevention and treatment of the common cold.

Search methods: We searched CENTRAL, MEDLINE, Embase, CINAHL, and LILACS to 22 May 2023, and searched Web of Science Core Collection and two trials registries to 14 June 2023. We also used reference checking, citation searching, and contact with study authors to identify additional studies.

Selection criteria: We included randomised controlled trials (RCTs) in children or adults that tested any form of zinc against placebo to prevent or treat the common cold or upper respiratory infection (URTI). We excluded zinc interventions in which zinc was combined with other minerals, vitamins, or herbs (e.g. a multivitamin, or mineral supplement containing zinc).

Data collection and analysis: We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We independently extracted data. When necessary, we contacted study authors for additional information. We assessed zinc (type and route) with placebo in the prevention and treatment of the common cold. Primary outcomes included the proportion of participants developing colds (for analyses of prevention trials only), duration of cold (measured in days from start to resolution of the cold), adverse events potentially due to zinc supplements (e.g. unpleasant taste, loss of smell, vomiting, stomach cramps, and diarrhoea), and adverse events considered to be potential complications of the common cold (e.g. respiratory bacterial infections).

Main results: We included 34 studies (15 prevention, 19 treatment) involving 8526 participants. Twenty-two studies were conducted on adults and 12 studies were conducted on children. Most trials were conducted in the USA (n = 18), followed by India, Indonesia, Iran, and Turkey (two studies each), and Australia, Burkina Faso, Colombia, Denmark, Finland, Tanzania, Thailand, and the UK (one study each). The 15 prevention studies identified the condition as either common cold (n = 8) or URTI (n = 7). However, almost all therapeutic studies (17/19) focused on the common cold. Most studies (17/34) evaluated the effectiveness of zinc administered as lozenges (3 prevention; 14 treatment) in acetate, gluconate, and orotate forms; gluconate lozenges were the most common (9/17). Zinc gluconate was given at doses between 45 and 276 mg/day for between 4.5 and 21 days. Five (5/17) lozenge studies gave acetate lozenges and two (2/17) gave both acetate and gluconate lozenges. One (1/17) lozenge study administered intranasal (gluconate) and lozenge (orotate) zinc in tandem for cold treatment. Of the 17/34 studies that did not use lozenges, 1/17 gave capsules, 3/17 administered dissolved powders, 5/17 gave tablets, 4/17 used syrups, and 4/17 used intranasal administration. Most studies were at unclear or high risk of bias in at least one domain. There may be little or no reduction in the risk of developing a cold with zinc compared to placebo (risk ratio (RR) 0.93, 95% CI 0.85 to 1.01; I2 = 20%; 9 studies, 1449 participants; low-certainty evidence). There may be little or no reduction in the mean number of colds that occur over five to 18 months of follow-up (mean difference (MD) -0.90, 95% CI -1.93 to 0.12; I2 = 96%; 2 studies, 1284 participants; low-certainty evidence). When colds occur, there is probably little or no difference in the duration of colds in days (MD -0.63, 95% CI -1.29 to 0.04; I² = 77%; 3 studies, 740 participants; moderate-certainty evidence), and there may be little or no difference in global symptom severity (standardised mean difference (SMD) 0.04, 95% CI -0.35 to 0.43; I² = 0%; 2 studies, 101 participants; low-certainty evidence). When zinc is used for cold treatment, there may be a reduction in the mean duration of the cold in days (MD -2.37, 95% CI -4.21 to -0.53; I² = 97%; 8 studies, 972 participants; low-certainty evidence), although it is uncertain whether there is a reduction in the risk of having an ongoing cold at the end of follow-up (RR 0.52, 95% CI 0.21 to 1.27; I² = 65%; 5 studies, 357 participants; very low-certainty evidence), or global symptom severity (SMD -0.03, 95% CI -0.56 to 0.50; I² = 78%; 2 studies, 261 participants; very low-certainty evidence), and there may be little or no difference in the risk of a change in global symptom severity (RR 1.02, 95% CI 0.85 to 1.23; 1 study, 114 participants; low-certainty evidence). Thirty-one studies reported non-serious adverse events (2422 participants). It is uncertain whether there is a difference in the risk of adverse events with zinc used for cold prevention (RR 1.11, 95% CI 0.84 to 1.47; I2 = 0%; 7 studies, 1517 participants; very low-certainty evidence) or an increase in the risk of serious adverse events (RR 1.67, 95% CI 0.78 to 3.57; I2 = 0%; 3 studies, 1563 participants; low-certainty evidence). There is probably an increase in the risk of non-serious adverse events when zinc is used for cold treatment (RR 1.34, 95% CI 1.15 to 1.55; I2 = 44%; 2084 participants, 16 studies; moderate-certainty evidence); no treatment study provided information on serious adverse events. No study provided clear information about adverse events considered to be potential complications of the common cold.

Authors' conclusions: The findings suggest that zinc supplementation may have little or no effect on the prevention of colds but may reduce the duration of ongoing colds, with an increase in non-serious adverse events. Overall, there was wide variation in interventions (including concomitant therapy) and outcomes across the studies, as well as incomplete reporting of several domains, which should be considered when making conclusions about the efficacy of zinc for the common cold.

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Conflict of interest statement

Daryl Nault: declares no conflict of interest.

Taryn Machingo: declares no conflict of interest.

Andrea G Shipper: declares no conflict of interest.

Daniel A Antiporta: declares no conflict of interest.

Candyce Hamel: declares no conflict of interest.

Sahar Nourouzpour: declares no conflict of interest.

Menelaos Konstantinidis: reports being a Statistical Editor for Cochrane Acute Respiratory Infections, but had no role in the editorial process of this review.

Erica Phillips: declares no conflict of interest.

Elizabeth Lipski: declares no conflict of interest.

L Susan Wieland: reports funding for Cochrane Complementary Medicine from the US National Institutes of Health, National Center for Complementary and Alternative Medicine, R24 AT001293; paid to institution.

Figures

1
1
2
2
3
3
4
4
1.1
1.1. Analysis
Comparison 1: Proportion of participants developing colds (for analyses of prevention trials only), with colds as defined by each study ‐ prevention, Outcome 1: Proportion of participants developing colds/URTI: primary analysis
2.1
2.1. Analysis
Comparison 2: Mean number of colds/URTIs developed (for analyses of prevention trials only), with colds as defined by each study ‐ prevention, Outcome 1: Mean number of colds/URTIs developed: primary analysis
3.1
3.1. Analysis
Comparison 3: Mean duration of colds (measured in days from start to resolution of the cold, as defined by each study) ‐ prevention, Outcome 1: Mean duration of colds/URTIs (prevention): primary analysis
4.1
4.1. Analysis
Comparison 4: Adverse events ‐ prevention, Outcome 1: Adverse events (prevention): primary analysis
4.2
4.2. Analysis
Comparison 4: Adverse events ‐ prevention, Outcome 2: Serious adverse events (prevention): primary analysis
5.1
5.1. Analysis
Comparison 5: Global severity of the cold (using a global measure, or by summing severity scores for individual symptoms) ‐ prevention, Outcome 1: Standardised mean global symptom severity (prevention)
6.1
6.1. Analysis
Comparison 6: Severity of individual cold symptoms (measured on a scale) ‐ prevention, Outcome 1: Severity of nasal congestion (prevention)
6.2
6.2. Analysis
Comparison 6: Severity of individual cold symptoms (measured on a scale) ‐ prevention, Outcome 2: Severity of nasal drainage (prevention)
6.3
6.3. Analysis
Comparison 6: Severity of individual cold symptoms (measured on a scale) ‐ prevention, Outcome 3: Severity of nasal symptoms (prevention)
7.1
7.1. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 1: Cough (continuous) (prevention)
7.2
7.2. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 2: Nasal drainage (continuous) (prevention)
7.3
7.3. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 3: Fever (continuous) (prevention)
7.4
7.4. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 4: Headache (continuous) (prevention)
7.5
7.5. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 5: Hoarseness (continuous) (prevention)
7.6
7.6. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 6: Muscle aches (continuous) (prevention)
7.7
7.7. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 7: Nasal congestion (continuous) (prevention)
7.8
7.8. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 8: Sneezing (continuous) (prevention)
7.9
7.9. Analysis
Comparison 7: Mean duration of individual cold symptoms ‐ prevention, Outcome 9: Sore throat (continuous) (prevention)
8.1
8.1. Analysis
Comparison 8: Days missed from work or school ‐ prevention, Outcome 1: Proportion of participants missing days from work or school (prevention)
8.2
8.2. Analysis
Comparison 8: Days missed from work or school ‐ prevention, Outcome 2: Mean days missed from work or school (prevention)
9.1
9.1. Analysis
Comparison 9: Mean duration of colds (measured in days from start to resolution of the cold, as defined by each study) ‐ treatment, Outcome 1: Mean duration of colds/URTIs (treatment): primary analysis
9.2
9.2. Analysis
Comparison 9: Mean duration of colds (measured in days from start to resolution of the cold, as defined by each study) ‐ treatment, Outcome 2: Subgroup analysis (treatment): all administration routes
9.3
9.3. Analysis
Comparison 9: Mean duration of colds (measured in days from start to resolution of the cold, as defined by each study) ‐ treatment, Outcome 3: Subgroup analysis (treatment): daily dose of zinc
10.1
10.1. Analysis
Comparison 10: Risk of cold/URTIs at end of study (measured in days from start to resolution of the cold, as defined by each study) ‐ treatment, Outcome 1: Risk of ongoing cold/URTIs at end of study (treatment): primary analysis
11.1
11.1. Analysis
Comparison 11: Adverse events ‐ treatment, Outcome 1: Adverse events (treatment): primary analysis
11.2
11.2. Analysis
Comparison 11: Adverse events ‐ treatment, Outcome 2: Subgroup analysis (treatment): intranasal vs lozenge
11.3
11.3. Analysis
Comparison 11: Adverse events ‐ treatment, Outcome 3: Subgroup analysis (treatment): zinc acetate vs zinc gluconate
11.4
11.4. Analysis
Comparison 11: Adverse events ‐ treatment, Outcome 4: Subgroup analysis (treatment): daily dose of zinc
11.5
11.5. Analysis
Comparison 11: Adverse events ‐ treatment, Outcome 5: Subgroup analysis (treatment): age groupings
12.1
12.1. Analysis
Comparison 12: Global severity of the cold (using a global measure, or by summing severity scores for individual symptoms) ‐ treatment, Outcome 1: Standardised mean global symptom severity (treatment)
12.2
12.2. Analysis
Comparison 12: Global severity of the cold (using a global measure, or by summing severity scores for individual symptoms) ‐ treatment, Outcome 2: Proportion with changes in global symptom severity (treatment)
13.1
13.1. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 1: Severity of cough (treatment)
13.2
13.2. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 2: Severity of headache (treatment)
13.3
13.3. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 3: Severity of hoarseness (treatment)
13.4
13.4. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 4: Severity of malaise (treatment)
13.5
13.5. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 5: Severity of muscle aches (treatment)
13.6
13.6. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 6: Severity of nasal congestion (treatment)
13.7
13.7. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 7: Severity of nasal drainage (treatment)
13.8
13.8. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 8: Severity of scratchy throat (treatment)
13.9
13.9. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 9: Severity of sneezing (treatment)
13.10
13.10. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 10: Severity of sore throat (treatment)
13.11
13.11. Analysis
Comparison 13: Severity of individual cold symptoms (measured on a scale) ‐ treatment, Outcome 11: Severity of fever (treatment)
14.1
14.1. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 1: Cough (continuous) (treatment)
14.2
14.2. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 2: Fever (continuous) (treatment)
14.3
14.3. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 3: Headache (continuous) (treatment)
14.4
14.4. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 4: Hoarseness (continuous) (treatment)
14.5
14.5. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 5: Malaise (continuous) (treatment)
14.6
14.6. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 6: Muscle aches (continuous) (treatment)
14.7
14.7. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 7: Nasal congestion (continuous) (treatment)
14.8
14.8. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 8: Nasal drainage (continuous) (treatment)
14.9
14.9. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 9: Scratchy throat (continuous) (treatment)
14.10
14.10. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 10: Sneezing (continuous) (treatment)
14.11
14.11. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 11: Sore throat (continuous) (treatment)
14.12
14.12. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 12: Nasal symptoms (continuous) (treatment)
14.13
14.13. Analysis
Comparison 14: Mean duration of individual cold symptoms ‐ treatment, Outcome 13: Throat symptoms (continuous) (treatment)
15.1
15.1. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 1: Cough (dichotomous) (treatment)
15.2
15.2. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 2: Fever (dichotomous) (treatment)
15.3
15.3. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 3: Headache (dichotomous) (treatment)
15.4
15.4. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 4: Hoarseness (dichotomous) (treatment)
15.5
15.5. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 5: Muscle aches (dichotomous) (treatment)
15.6
15.6. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 6: Nasal congestion (dichotomous) (treatment)
15.7
15.7. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 7: Nasal drainage (dichotomous) (treatment)
15.8
15.8. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 8: Scratchy throat (dichotomous) (treatment)
15.9
15.9. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 9: Sneezing (dichotomous) (treatment)
15.10
15.10. Analysis
Comparison 15: Number of individual cold symptoms by end of study ‐ treatment, Outcome 10: Sore throat (dichotomous) (treatment)
16.1
16.1. Analysis
Comparison 16: Days missed from work or school ‐ treatment, Outcome 1: Proportion of participants missing days from work or school (treatment)
16.2
16.2. Analysis
Comparison 16: Days missed from work or school ‐ treatment, Outcome 2: Proportion of days absent from work or school (treatment)
See this image and copyright information in PMC

Update of

  • doi: 10.1002/14651858.CD014914

References

References to studies included in this review

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    1. Somé JW, Abbeddou S, Yakes Jimenez E, Hess SY, Ouédraogo ZP, Guissou RM, et al. Effect of zinc added to a daily small-quantity lipid-based nutrient supplement on diarrhoea, malaria, fever and respiratory infections in young children in rural Burkina Faso: a cluster-randomised trial. BMJ Open 2015;5(9):e007828. [DOI: 10.1136/bmjopen-2015-007828] - DOI - PMC - PubMed
Turner 2000 challenge {published data only}
    1. Turner RB, Cetnarowski WE. Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds. Clinical Infectious Diseases 2000;31(5):1202-8. [DOI: 10.1086/317437] [PMID: ] - DOI - PubMed
Turner 2000 natural {published data only (unpublished sought but not used)}
    1. Turner RB, Cetnarowski WE. Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds. Clinical Infectious Diseases 2000;31(5):1202-8. [DOI: 10.1086/317437] [PMID: ] - DOI - PubMed
Turner 2001 {published data only}
    1. Turner RB. Ineffectiveness of intranasal zinc gluconate for prevention of experimental rhinovirus colds. Clinical Infectious Diseases 2001;33(11):1865-70. [DOI: 10.1086/324347] - DOI - PubMed
Vakili 2009 {published data only}
    1. Vakili R, Vahedian M, Khodaei G, Mahmoudi M. Effects of zinc supplementation in occurrence and duration of common cold in school aged children during cold season: a double-blind placebo-controlled trial. Iranian Journal of Pediatrics 2009;19(4):376-80.
Weismann 1990 {published data only}
    1. Weismann K, Jakobsen JP, Weismann JE, Hammer UM, Nyholm SM, Hansen B, et al. Zinc gluconate lozenges for common cold. A double-blind clinical trial. Danish Medical Bulletin 1990;37(3):279-81. - PubMed

References to studies excluded from this review

Abdulhamid 2008 {published data only}
    1. Abdulhamid I, Beck FW, Millard S, Chen X, Prasad A. Effect of zinc supplementation on respiratory tract infections in children with cystic fibrosis. Pediatric Pulmonology 2008;43(3):281-7. [DOI: 10.1002/ppul.20771] - DOI - PubMed
Australian Journal of Pharmacy 2011 {published data only}
    1. Zinc reduces the duration and severity of the common cold in healthy people. Australian Journal of Pharmacy 2011;92(1093):86.
Bansal 2011 {published data only}
    1. Bansal A, Parmar VR, Basu S, Kaur J, Jain S, Saha A, et al. Zinc supplementation in severe acute lower respiratory tract infection in children: a triple-blind randomized placebo controlled trial. Indian Journal of Pediatrics 2011;78(1):33-7. [DOI: 10.1007/s12098-010-0244-5] - DOI - PubMed
Barffour 2020 {published data only}
    1. Barffour MA, Hinnouho G-M, Wessells KR, Kounnavong S, Ratsavong K, Sitthideth D, et al. Effects of therapeutic zinc supplementation for diarrhea and two preventive zinc supplementation regimens on the incidence and duration of diarrhea and acute respiratory tract infections in rural Laotian children: a randomized controlled trial. Journal of Global Health 2020;10(1):010424. [DOI: 10.7189/jogh.10.010424] - DOI - PMC - PubMed
Bates 1993 {published data only}
    1. Bates CJ, Evans PH, Dardenne M, Prentice A, Lunn PG, Northrop-Clewes CA, et al. A trial of zinc supplementation in young rural Gambian children. British Journal of Nutrition 1993;69(1):243-55. [DOI: 10.1079/bjn19930026] - DOI - PubMed
Brown 2007 {published data only}
    1. Brown KH, López de Romaña D, Arsenault JE, Peerson JM, Penny ME. Comparison of the effects of zinc delivered in a fortified food or a liquid supplement on the growth, morbidity, and plasma zinc concentrations of young Peruvian children. American Journal of Clinical Nutrition 2007;85(2):538-47. [DOI: 10.1093/ajcn/85.2.538] - DOI - PubMed
Chandyo 2010 {published data only}
    1. Chandyo RK, Shrestha PS, Valentiner-Branth P, Mathisen M, Basnet S, Ulak M, et al. Two weeks of zinc administration to Nepalese children with pneumonia does not reduce the incidence of pneumonia or diarrhea during the next six months. Journal of Nutrition 2010;140(9):1677-82. [DOI: 10.3945/jn.109.117978] - DOI - PubMed
Girard 1991 {published data only}
    1. Girard JP, Terki N. Zinc gluconate in the treatment of rhinitis due to graminaceous pollen. Revue Francaise d'Allergologie 1991;31(3):157-60.
Habibian 2013 {published data only}
    1. Habibian R, Khoshdel A, Kheiri S, Torabi A. The effect of zinc sulphate syrup on children’s respiratory tract infections [اثر شربت سولفات روی بر عالئم بالینی کودکان بستری مبتال به عفونت های تنفسی]. Journal of Babol University of Medical Sciences 2013;15(4):22-9.
    1. IRCT201103025951N1. Zinc effect on respiratory infections [Zinc sulfate effect on children with respiratory infection]. https://en.irct.ir/trial/6427 (first received 17 June 2011).
Khera 2020 {published data only}
    1. Khera D, Singh S, Purohit P, Sharma P, Singh K. Prevalence of zinc deficiency and the effect of zinc supplementation on the prevention of acute respiratory infections. Turkish Thoracic Journal 2020;21(6):371-6. [DOI: 10.5152/TurkThoracJ.2019.19020] - DOI - PMC - PubMed
Kujinga 2018 {published data only}
    1. Kujinga P, Galetti V, Onyango E, Jakab V, Buerkli S, Andang'o P, et al. Effectiveness of zinc-fortified water on zinc intake, status and morbidity in Kenyan pre-school children: a randomised controlled trial. Public Health Nutrition 2018;21(15):2855-65. [DOI: 10.1017/S1368980018001441] - DOI - PMC - PubMed
Lira 1998 {published data only}
    1. Lira PI, Ashworth A, Morris SS. Effect of zinc supplementation on the morbidity, immune function, and growth of low-birth-weight, full-term infants in northeast Brazil. American Journal of Clinical Nutrition 1998;68(Suppl 2):418-24. [DOI: 10.1093/ajcn/68.2.418S] - DOI - PubMed
Long 2006 {published data only}
    1. Long KZ, Montoya Y, Hertzmark E, Santos JI, Rosado JL. A double-blind, randomized, clinical trial of the effect of vitamin A and zinc supplementation on diarrheal disease and respiratory tract infections in children in Mexico City, Mexico. American Journal of Clinical Nutrition 2006;83(3):693-700. [DOI: 10.1093/ajcn.83.3.693] - DOI - PubMed
Luabeya 2007 {published data only}
    1. Luabeya KK, Mpontshane N, Mackay M, Ward H, Elson I, Chhagan M, et al. Zinc or multiple micronutrient supplementation to reduce diarrhea and respiratory disease in South African children: a randomized controlled trial. PLOS One 2007;2(6):e541. [DOI: 10.1371/journal.pone.0000541] - DOI - PMC - PubMed
Maggini 2012 {published data only}
    1. Maggini S, Beveridge S, Suter M. A combination of high-dose vitamin C plus zinc for the common cold. Journal of International Medical Research 2012;40(1):28-42. [DOI: 10.1177/147323001204000104] - DOI - PubMed
Makonnen 2003 {published data only}
    1. Makonnen B, Venter A, Joubert G. A randomized controlled study of the impact of dietary zinc supplementation in the management of children with protein-energy malnutrition in Lesotho. II: Special investigations. Journal of Tropical Pediatrics 2003;49(6):353-60. [DOI: 10.1093/tropej/49.6.353] - DOI - PubMed
Martinez‐Estevez 2016 {published data only}
    1. Martinez-Estevez NS, Alvarez-Guevara AN, Rodriguez-Martinez CE. Effects of zinc supplementation in the prevention of respiratory tract infections and diarrheal disease in Colombian children: a 12-month randomised controlled trial. Allergologia et Immunopathologia 2016;44(4):368-75. [DOI: 10.1016/j.aller.2015.12.006] - DOI - PubMed
Masoodpoor 2008 {published data only}
    1. Masoodpoor N, Darakhshan S, Darakhshan D, Tabatabaei ST, Mosavat SA. Impact of zinc supplementation on respiratory and gastrointestinal infections: a double-blind, randomized trial among urban Iranian school children. Pediatrics 2008;121(Suppl 2):S153-4.
McElroy 2003 {published data only}
    1. McElroy BH, Miller SP, McElroy BH, Miller SP. An open-label, single-center, phase IV clinical study of the effectiveness of zinc gluconate glycine lozenges (Cold-Eeze) in reducing the duration and symptoms of the common cold in school-aged subjects. American Journal of Therapeutics 2003;10(5):324-9. [DOI: 10.1097/00045391-200309000-00004] - DOI - PubMed
Meeks Gardner1998 {published data only}
    1. Meeks Gardner J, Witter MM, Ramdath DD. Zinc supplementation: effects on the growth and morbidity of undernourished Jamaican children. European Journal of Clinical Nutrition 1998;52(1):34-9. [DOI: 10.1038/sj.ejcn.1600509] - DOI - PubMed
NCT01092039 {published data only}
    1. NCT01092039. Safety and efficacy study of oral XIGO tablets to treat the common cold [XIGO effectiveness study: an investigation of the safety and efficacy of oral XIGO tablets on patients diagnosed with the common cold]. www.clinicaltrials.gov/study/NCT01092039 (first submitted 22 March 2010).
NCT04672850 {published data only}
    1. NCT04672850. The effect of probiotic and zinc supplementation on the common cold [The effect of probiotic and zinc supplementation on the common cold in healthy adults]. clinicaltrials.gov/ct2/show/NCT04672850 (first received 3 December 2020).
Ninh 1996 {published data only}
    1. Ninh NX, Thissen JP, Collette L, Gerard G, Khoi HH, Ketelslegers JM. Zinc supplementation increases growth and circulating insulin-like growth factor I (IGF-I) in growth-retarded Vietnamese children. American Journal of Clinical Nutrition 1996;63(4):514-9. [DOI: 10.1093/ajcn/63.4.514] - DOI - PubMed
Penny 2004 {published data only}
    1. Penny ME, Marin RM, Duran A, Peerson JM, Lanata CF, Lönnerdal B, et al. Randomized controlled trial of the effect of daily supplementation with zinc or multiple micronutrients on the morbidity, growth, and micronutrient status of young Peruvian children. American Journal of Clinical Nutrition 2004;79(3):457-65. [DOI: 10.1093/ajcn/79.3.457] - DOI - PubMed
Rahman 2001 {published data only}
    1. Rahman MM, Vermund SH, Wahed MA, Fuchs GJ, Baqui AH, Alvarez JO. Simultaneous zinc and vitamin A supplementation in Bangladeshi children: randomised double blind controlled trial. BMJ 2001;323(7308):314-8. [DOI: 10.1136/bmj.323.7308.314] - DOI - PMC - PubMed
Richard 2006 {published data only}
    1. Richard SA, Zavaleta N, Caulfield LE, Black RE, Witzig RS, Shankar AH. Zinc and iron supplementation and malaria, diarrhea, and respiratory infections in children in the Peruvian Amazon. American Journal of Tropical Medicine and Hygiene 2006;75(1):126-32. [DOI: 10.4269/ajtmh.2006.75.1.0750126] - DOI - PubMed
Roy 1999 {published data only}
    1. Roy SK, Tomkins AM, Akramuzzaman SM, Chakraborty B, Ara G, Biswas R, et al. Impact of zinc supplementation on subsequent morbidity and growth in Bangladeshi children with persistent diarrhoea. Journal of Health, Population, and Nutrition 2007;25(1):67-74. [PMCID: PMC3013265] [PMID: ] - PMC - PubMed
    1. Roy SK, Tomkins AM, Haider R, Behren RH, Akramuzzaman SM, Mahalanabis D, et al. Impact of zinc supplementation on subsequent growth and morbidity in Bangladeshi children with acute diarrhoea. European Journal of Clinical Nutrition 1999;53(7):529‐34. [DOI: DOI: 10.1038/sj.ejcn.1600734] - PubMed
Ruel 1997 {published data only}
    1. Ruel MT, Rivera JA, Santizo MC, Lönnerdal B, Brown KH. Impact of zinc supplementation on morbidity from diarrhea and respiratory infections among rural Guatemalan children. Pediatrics 1997;99(6):808-13. [DOI: 10.1542/peds.99.6.808] - DOI - PubMed
Sampaio 2013 {published data only}
    1. Sampaio DL, De Mattos ÂP, Ribeiro TC, De Leite ME, Cole CR, Costa-Ribeiro H Jr. Zinc and other micronutrients supplementation through the use of sprinkles [Suplementação de zinco e outros micronutrientes através do uso de sprinkles: impacto na ocorrência de doença diarreica e infecções respiratórias em crianças institucionalizadas^ipt]. Jornal de Pediatria 2013;89(3):286-93. - PubMed
Sempértegui 1996 {published data only}
    1. Sempértegui F, Estrella B, Correa E, Aguirre L, Saa B, Torres M, et al. Effects of short-term zinc supplementation on cellular immunity, respiratory symptoms, and growth of malnourished Equadorian children. European Journal of Clinical Nutrition 1996;50(1):42-6. - PubMed
Shaker 2018 {published data only}
    1. Shaker SM, Fathy H, Abdelall EK, Said AS. The effect of zinc and Vitamin A supplements in treating and reducing the incidence of upper respiratory tract infections in children. National Journal of Physiology Pharmacy and Pharmacology 2018;8(7):1010-7. [DOI: 10.5455/njppp.2018.8.0104206032018] - DOI
Silk 2005 {published data only}
    1. Silk R, LeFante C. Safety of zinc gluconate glycine (Cold-Eeze) in a geriatric population: a randomized, placebo-controlled, double-blind trial. American Journal of Therapeutics 2005;12(6):612-7. [DOI: 10.1097/01.mjt.0000179115.04316.18] - DOI - PubMed
Smith 1991 {published data only}
    1. Smith AP, Tyrrell DA, Al-Nakib W, Barrow I, Higgins P, Wenham R. Effects of zinc gluconate and nedocromil sodium on performance deficits produced by the common cold. Journal of Psychopharmacology 1991;5(3):251-4. - PubMed
Taneja 2006 {published data only}
    1. Taneja S, Bhandari N, Rongsen-Chandola T, Mahalanabis D, Fontaine O, Bhan MK. Impact of zinc supplementation in low birth weight infants on severe morbidity, mortality and zinc status: a randomized controlled trial. https://www.clinicaltrials.gov/study/NCT00272142 (first received 3 January 2006).
Veverka 2009 {published data only}
    1. Veverka DV, Wilson C, Martinez MA, Wenger R, Tamosuinas A. Use of zinc supplements to reduce upper respiratory infections in United States Air Force Academy cadets. Complementary Therapies in Clinical Practice 2009;15(2):91-5. [DOI: 10.1016/j.ctcp.2009.02.006] - DOI - PubMed
Walker 2007 {published data only}
    1. Walker CL, Bhutta ZA, Bhandari N, Teka T, Shahid F, Taneja S, et al. Zinc during and in convalescence from diarrhea has no demonstrable effect on subsequent morbidity and anthropometric status among infants <6 mo of age. American Journal of Clinical Nutrition 2007;85(3):887-94. [DOI: 10.1093/ajcn/85.3.887] - DOI - PubMed
Yousefichaijan 2017 {published data only}
    1. IRCT138903184056N2. Effectiveness of zinc sulfate in common cold symptoms in children [Evaluation of the effectiveness of zinc sulfate in reducing duration of common cold symptoms in children]. https://www.irct.ir/trial/4235 (first received 14 June 2010).
    1. Yousefichaijan P, Dorreh F, Naziri M. The effect of zinc sulfate on duration of common cold symptoms in children. Journal of Biology and Today's World 2017;6(10):186-90.

References to studies awaiting assessment

Bobat 2005 {published data only}
    1. Bobat R, Coovadia H, Stephen C, Naidoo KL, McKerrow N, Black RE, et al. Safety and efficacy of zinc supplementation for children with HIV-1 infection in South Africa: a randomised double-blind placebo-controlled trial. Lancet 2005;366(9500):1862-7. [DOI: 10.1016/S0140-6736(05)67756-2] - DOI - PubMed
NCT05002101 {published data only}
    1. NCT05002101. Daily zinc supplement effect on prevention of diarrhea and acute respiratory infections in children less than five years [The effect of daily zinc supplementation on prevention of diarrhea and acute respiratory infections among children less than five years: a randomized controlled trial]. clinicaltrials.gov/study/NCT05002101 (first received 1 August 2018).
Osendarp 2001 {published data only}
    1. Osendarp SJ, Raaij JM, Darmstadt GL, Baqui AH, Hautvast JG, Fuchs GJ. Zinc supplementation during pregnancy and effects on growth and morbidity in low birthweight infants: a randomised placebo controlled trial. Lancet 2001;357(9262):1080‐5. [DOI: 10.1016/s0140-6736(00)04260-4] - DOI - PubMed
Wuehler 2008 {published data only}
    1. Wuehler SE, Sempértegui F, Brown KH. Dose-response trial of prophylactic zinc supplements, with or without copper, in young Ecuadorian children at risk of zinc deficiency. American Journal of Clinical Nutrition 2008 ;87(3):723-33. [DOI: 10.1093/ajcn/87.3.723] - DOI - PubMed

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References to other published versions of this review

Wieland 2021
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