Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials.

Li Ran, Wenli Zhao, Jingxia Wang, Hongwu Wang, Ye Zhao, Yiider Tseng, Huaien Bu

Journal: BioMed research international 2019;2018():1837634

PMID: 30069463

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Plain Language Summary

The common cold poses a heavy burden worldwide, in terms of human health and economic losses. The aim of this meta-analysis was to evaluate whether vitamin C could be used for relieving symptoms, shortening the duration, or reducing the incidence of the common cold. Nine randomised controlled trials conducted between 1950 and 2001 were included in the meta-analysis. No statistically significant effects were found when vitamin C was only started at the onset of symptoms, but regular supplementation with therapeutic doses of vitamin C at the onset of illness shortened the duration of the common cold and the time confined indoors, and relieved the symptoms, including chest pain, fever and chills. Based on this meta-analysis the authors recommend a small daily dose of vitamin C (no more than 1.0g/day) to support immunity and a larger dose of vitamin C during the common cold (a larger dose than before, usually 3.0 g/day to 4.0 g/day) to better recover health.

Abstract

AIM

To investigate whether vitamin C is effective in the treatment of the common cold.

METHOD

After systematically searching the National Library of Medicine (PubMed), Cochrane Library, Elsevier, China National Knowledge Infrastructure (CNKI), VIP databases, and WANFANG databases, 9 randomized placebo-controlled trials were included in our meta-analysis in RevMan 5.3 software, all of which were in English.

RESULTS

In the evaluation of vitamin C, administration of extra therapeutic doses at the onset of cold despite routine supplementation was found to help reduce its duration (mean difference (MD) = -0.56, 95% confidence interval (CI) [-1.03, -0.10], and P = 0.02), shorten the time of confinement indoors (MD = -0.41, 95% CI [-0.62, -0.19], and P = 0.0002), and relieve the symptoms associated with it, including chest pain (MD = -0.40, 95% CI [-0.77, -0.03], and P = 0.03), fever (MD = -0.45, 95% CI [-0.78, -0.11], and P = 0.009), and chills (MD = -0.36, 95% CI [-0.65, -0.07], and P = 0.01).

CONCLUSIONS

Extra doses of vitamin C could benefit some patients who contract the common cold despite taking daily vitamin C supplements.

Address: Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.; Department of Neurology, Nankai Hospital, Tianjin Academy of Integrative Medicine, Tianjin 300100, China.; Department of Research and Development, Hangzhou DeBuYou Health Technology Co. Ltd., Hangzhou, Zhejiang 310018, China.; College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.; Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, USA.

DOI: 10.1155/2018/1837634