Vitamin C and the Common Cold -papers

by Harri Hemilš


Department of Public Health
University of Helsinki, Finland
harri.hemila@helsinki.fi
http://www.mv.helsinki.fi/home/hemila
Feb 18, 2020

The papers on the common cold are divided in categories and if the same paper falls into several categories, it is listed in each of them

  1. Cochrane Review on vitamin C and the common cold; and other Reviews
  2. Vitamin C and the incidence of colds
  3. Vitamin C and common cold duration and severity
  4. Vitamin C and exercise-related respiratory infections
  5. Vitamin C and complications of the common cold: exacerbation of asthma
  6. Possible mechanism of vitamin C effect on colds
  7. Linus Pauling and the common cold
  8. Letters and commentaries


Cochrane Review on vitamin C and the common cold; and other Reviews

On February 2018, this review had the highest Altmetric score out of  8855 Cochrane reviews:
http://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2018Feb.htm
On February 2020, this review had the highest Altmetric score out of  10900 Cochrane reviews:
http://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2020Feb.htm


Hemilš H, Chalker EB.
Vitamin C for preventing and treating the common cold.
Cochrane Database Syst Rev 2013; CD000980

References to the review and updated 2016 version:
http://www.mv.helsinki.fi/home/hemila/CC

https://doi.org/10.1002/14651858.CD000980.pub4
http://www.mv.helsinki.fi/home/hemila/CC/2013_Coch_Colds_CD000980.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23440782

     Discussions:
     Hemilš H.
     Commentaries on ‘Vitamin C for Preventing and Treating the Common Cold’ with a response from the review author
     [Reply to Bax, Spee and Madderom].
     [Reply to Shamseer and Vohra].
     Evidence-Based Child Health: A Cochrane Review Journal 2008;3:724-728
     http://dx.doi.org/10.1002/ebch.261
     http://www.mv.helsinki.fi/home/hemila/H/2008_L_EBCH.pdf


Summary of vitamin C, vitamin E, zinc lozenge  studies on the common cold:
Hemilš H. Vitamins and minerals [book chapter].
In: "Common cold " (Eccles R, Weber O, eds.)
Birkhauser Verlag, 2009:275-307
Abstract and references:
http://www.mv.helsinki.fi/home/hemila/birkhauser
Available at:
http://dx.doi.org/10.1007/978-3-7643-9912-2_13
http://www.springer.com/birkhauser/biosciences/book/978-3-7643-9894-1
http://www.amazon.com/Common-Birkh%C3%A4user-Advances-Infectious-Diseases/dp/3764398949


Short summary:
Douglas RM, Hemilš H. Vitamin C for preventing and treating the common cold.
PLoS Med 2005;2:e168
http://dx.doi.org/10.1371/journal.pmed.0020168

Short summary:
Hemilš H. Vitamin C, respiratory infections, and the immune system.
Trends Immunol 2003;24:579-580
http://dx.doi.org/10.1016/j.it.2003.09.004

Hemilš H, Douglas RM. Vitamin C and acute respiratory infections.
Int J TB Lung Disease 1999;3:756-761
http://www.ingentaconnect.com/content/iuatld/ijtld/1999/00000003/00000009/art00004
http://www.mv.helsinki.fi/home/hemila/H/HH_1999_IJTLD.pdf



Vitamin C and the incidence of colds

Although there is strong evidence that vitamin C does not decrease the averge incidence of colds in the general community, there is strong evidence that some sub-populations benefit of vitamin C, so that colds are prevented in them:
Hemilš H. Prophylactic benefit of vitamin C in large trials (Table 20).
In: Do vitamins C and E affect respiratory infections? Thesis 2006 pp. 44
http://hdl.handle.net/10138/20335

Strong evidence that in some conditions males and females differ:

Hemilš H. Vitamin C and sex differences in respiratory tract infections.
Respir Med 2008;102:625-626
http://dx.doi.org/10.1016/j.rmed.2007.12.011
https://helda.helsinki.fi/handle/10250/8280
http://www.mv.helsinki.fi/home/hemila/H/2008_L_RespMed.pdf 

Effects of vitamin C on military personnel may be explained by heavy physical stress or/and crowding of people:
Hemilš H. Vitamin C supplementation and respiratory infections: a systematic review. Mil Med 2004;169:920-925
https://doi.org/10.7205/MILMED.169.11.920
http://www.mv.helsinki.fi/home/hemila/H/HH_2004.pdf

Dietary vitamin C had no correlatin with cold incidence in middle-aged male smokers:
Hemilš H, Kaprio J, Albanes D, Heinonen OP, Virtamo J.
Vitamin C, vitamin E and beta-carotene in relation to common cold incidence in male smokers. Epidemiology 2002;13:32-37
http://dx.doi.org/10.1097/00001648-200201000-00006
http://www.jstor.org/pss/3703244
http://hdl.handle.net/10138/18059  

Studies with males in the UK found decrease in common cold incidence; the explanation may be low dietary vitamin C intake when the trials were carried out:
Hemilš H. Vitamin C intake and susceptibility to the common cold.
Br J Nutr 1997;77:59-72 [Discussion in: 1997;78:857-866, see below]
http://dx.doi.org/10.1017/S0007114500002889
https://helda.helsinki.fi/handle/10138/13886
http://www.mv.helsinki.fi/home/hemila/H/HH_1997_BJN.pdf
    Discussion:
    Hemilš H. Vitamin C intake and susceptibility to the common cold – Reply.
Br J Nutr 1997;78:861-866
    http://dx.doi.org/10.1079/BJN19970201
    https://helda.helsinki.fi/handle/10138/223364
    http://www.mv.helsinki.fi/home/hemila/H/HH_1997_BJN2.pdf

Another presentation of the UK study findings:
Hemilš H. Prophylactic effect of vitamin C on recurrent colds in the UK trials (Table 22).
In: Do vitamins C and E affect respiratory infections? Thesis 2006 pp. 46-47
http://hdl.handle.net/10138/20335


The first meta-analysis on the effect of vitamin C on people under heavy short-term physical stress which was based on 3 RCTs; after this paper 4 new RCTs found benefit of vitamin C for heavy short-term physical stress (see the Cochrane review)
Hemilš H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress.
Int J Sports Med 1996;17:379-383
http://dx.doi.org/10.1055/s-2007-972864
https://helda.helsinki.fi/handle/10138/225881
http://www.mv.helsinki.fi/home/hemila/H/HH_1996_IJSM.pdf

Analysis of the incidence of colds in studies with 1 g/day or more of vitamin C each day over the study:
Hemilš H. Does vitamin C alleviate the symptoms of the common cold? A review of current evidence.
Scand J Infect Dis 1994;26:1-6
http://dx.doi.org/10.3109/00365549409008582
https://helda.helsinki.fi/handle/10138/228102
http://www.mv.helsinki.fi/home/hemila/H/HH_1994.pdf

Analysis of the incidence of colds in studies with 1 g/day or more of vitamin C each day over the study:
Hemilš H. Vitamin C and the common cold.
Br J Nutr 1992;67:3-16
http://dx.doi.org/10.1079/BJN19920004
http://www.mv.helsinki.fi/home/hemila/H/HH_1992.pdf

Vitamin C and common cold duration and severity

Vitamin C halved the duration of colds in male adloescent swimmers but not in female adolescent swimmers:
Constantini NW, Dubnov-Raz G, Eyal BB, Berry EM, Cohen AH, Hemilš H.
The effect of vitamin C on upper respiratory infections in adolescent swimmers: a randomized trial.
Eur J Pediatrics 2011;170:59-63
http://dx.doi.org/10.1007/s00431-010-1270-z
https://helda.helsinki.fi/handle/10138/228085
http://www.mv.helsinki.fi/home/hemila/H/HH_2011_EurJPediatr.pdf 

Effects of vitamin C on military personnel may be explained by heavy physical stress or/and crowding of people:
Hemilš H. Vitamin C supplementation and respiratory infections: a systematic review.
Mil Med 2004;169:920-925
https://doi.org/10.7205/MILMED.169.11.920
http://www.mv.helsinki.fi/home/hemila/H/HH_2004.pdf

On average the benefit of vitamin C has been greater in adults than in children, and with a dose of 2 g/day or more compared with 1 g/day.
Hemilš H. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit.
Med Hypotheses 1999;52:171-178
http://dx.doi.org/10.1054/mehy.1997.0639
https://helda.helsinki.fi/handle/10138/223761
http://www.mv.helsinki.fi/home/hemila/H/HH_1999_MH.pdf

Analysis of the duration and severity of colds in studies with 1 g/day or more of vitamin C each day over the study:
Hemilš H. Does vitamin C alleviate the symptoms of the common cold? A review of current evidence.
Scand J Infect Dis 1994;26:1-6
http://dx.doi.org/10.3109/00365549409008582
https://helda.helsinki.fi/handle/10138/228102
http://www.mv.helsinki.fi/home/hemila/H/HH_1994.pdf

Analysis of the duration and severity of colds in studies with 1 g/day or more of vitamin C each day over the study:
Hemilš H. Vitamin C and the common cold. Br J Nutr 1992;67:3-16
http://dx.doi.org/10.1079/BJN19920004
http://www.mv.helsinki.fi/home/hemila/H/HH_1992.pdf


Vitamin C and exercise-related respiratory symptoms

Vitamin C halved the duration of colds in male adloescent swimmers but not in female adolescent swimmers:
Constantini NW, Dubnov-Raz G, Eyal BB, Berry EM, Cohen AH, Hemilš H.
The effect of vitamin C on upper respiratory infections in adolescent swimmers: a randomized trial.

Eur J Pediatrics 2011;170:59-63
http://dx.doi.org/10.1007/s00431-010-1270-z
https://helda.helsinki.fi/handle/10138/228085
http://www.mv.helsinki.fi/home/hemila/H/HH_2011_EurJPediatr.pdf 


Effects of vitamin C on military personnel may be explained by heavy physical stress or/and crowding of people:
Hemilš H. Vitamin C supplementation and respiratory infections: a systematic review.
Mil Med 2004;169:920-925
http://dx.doi.org/10.7205/MILMED.169.11.920
http://www.mv.helsinki.fi/home/hemila/H/HH_2004.pdf

The first meta-analysis on the effect of vitamin C on people under heavy short-term physical stress which was based on 3 RCTs; after this paper 4 new RCTs found benefit of vitamin C for heavy short-term physical stress (see the Cochrane review)
Hemilš H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress.
Int J Sports Med 1996;17:379-383
http://dx.doi.org/10.1055/s-2007-972864
https://helda.helsinki.fi/handle/10138/225881
http://www.mv.helsinki.fi/home/hemila/H/HH_1996_IJSM.pdf


Comments on vitamin C and exercise studies:

Hemilš H. Evidence-based medicine and the role of antioxidants in physically-stressed people.
Nutrition Rev 2009;67:61-63
http://dx.doi.org/10.1111/j.1753-4887.2008.00134.x
https://helda.helsinki.fi/handle/10138/228068
http://www.mv.helsinki.fi/home/hemila/H/2009_L_NutRev.pdf 

Hemilš H. Vitamin C and exercise-induced immunodepression.
Eur J Clin Nutr 2007;61:1241-1242
http://dx.doi.org/10.1038/sj.ejcn.1602751
https://helda.helsinki.fi/handle/10250/135144
http://www.mv.helsinki.fi/home/hemila/H/2007_L_EJCN.pdf 

Hemilš H. Small trials focusing on surrogate end points may be uninformative.
Eur J Applied Physiology 2007;99:707-708
http://dx.doi.org/10.1007/s00421-006-0387-2
https://helda.helsinki.fi/handle/10250/8080
http://www.mv.helsinki.fi/home/hemila/H/2007_L_EJAP.pdf 

Vitamin C and complications of the common cold: exacerbation of asthma

Hemilš H. Vitamin C and common cold-induced asthma: a systematic review and statistical analysis.
Allergy, Asthma Clin Immunol 2013;9:46
http://dx.doi.org/10.1186/1710-1492-9-46
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4018579 

Linus Pauling and the common cold

Hemilš H. Vitamin C and the common cold; Meta-analysis; Pauling's meta-analyses (1971a,b);
In: Do vitamins C and E affect respiratory infections? Thesis 2006 pp. 11-13, 28, 35-36
http://hdl.handle.net/10138/20335
http://www.mv.helsinki.fi/home/hemila/pauling

Hemilš H. Vitamin C supplementation and the common cold - was Linus Pauling right or wrong?
Int J Vitam Nutr Res 1997;67:329-335
https://helda.helsinki.fi/handle/10250/7980
http://www.mv.helsinki.fi/home/hemila/H/HH_1997_IJVNR.pdf
http://www.ncbi.nlm.nih.gov/pubmed/9350474

Letters and commentaries

Hemilš H, Chalker E.
Meta-analysis on vitamin C and the common cold in children may be misleading.
Eur J Clin Pharmacol
https://doi.org/10.1007/s00228-019-02733-x
https://www.ncbi.nlm.nih.gov/pubmed/31377890
https://www.mv.helsinki.fi/home/hemila/H/Vorilhon_2019_Problems.pdf
https://www.mv.helsinki.fi/home/hemila/H/Vorilhon_2019_Problems_Supplement.pdf

Hemilš H. The effect of vitamin C on the common cold.
J Pharmacy Practice 2011;24:241-242
http://dx.doi.org/10.1177/0897190010392376
https://helda.helsinki.fi/handle/10138/228058

Hemilš H. Randomised trials on vitamin C.
Br J Nutr 2011;105:485-487
http://dx.doi.org/10.1017/S000711451000351X
http://www.ncbi.nlm.nih.gov/pubmed/20979683

Hemilš H. The role of vitamin C in the treatment of the common cold.
Am Family Phys 2007;76:1111, 1115
http://www.aafp.org/afp/2007/1015/p1111a.html
http://www.mv.helsinki.fi/home/hemila/H/2007_L_AFP_2p.pdf