Vitamin C Supplementation for the Treatment of COVID-19: A Systematic Review and Meta-Analysis
Monika Olczak-Pruc, Damian Swieczkowski, Jerzy R Ladny, Michal Pruc, Raul Juarez-Vela, Zubaid Rafique, Frank W Peacock, Lukasz Szarpak
Nutrients, doi:10.3390/nu14194217
Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2), millions of people have died, and the medical system has faced significant difficulties. Our purpose was to perform a meta-analysis to estimate the effect of vitamin C on in-hospital mortality and the ICU or hospital length of stay for patients diagnosed with COVID-19. We conducted a systematic review with meta-analysis in the following databases: PubMed, Web of Science, Scopus and Cochrane Central Register of Controlled Trials. We included studies that evaluated the effect of vitamin C supplementation, compared with standard treatment in COVID-19 patients who are ≥18 y of age. Nineteen trials were included in the meta-analysis. In-hospital mortality with and without vitamin C supplementation was 24.1% vs. 33.9% (OR = 0.59; 95%CI: 0.37 to 0.95; p = 0.03), respectively. Sub-analysis showed that, in randomized clinical trials, in-hospital mortality varied and amounted to 23.9% vs. 35.8% (OR = 0.44; 95%CI: 0.25 to 0.76; p = 0.003), respectively. In the non-randomized trials, in-hospital mortality was 24.2% vs. 33.5% (OR = 0.72; 95%CI: 0.38 to 1.39; p = 0.33), respectively. The ICU length of stay was longer in patients treated with vitamin C vs. standard therapy, 11.1 (7.3) vs. 8.3 (4.7) days (MD = 1.91; 95%CI: 0.89 to 2.93; p < 0.001), respectively. Acute kidney injury in patients treated with and without vitamin C varied and amounted to 27.8% vs. 45.0% (OR = 0.56; 95%CI: 0.40 to 0.78; p < 0.001), respectively. There were no differences in the frequency of other adverse events among patients' treatment with and without vitamin C (all p > 0.05). The use of vitamin C reduces hospital mortality. The length of stay in the ICU is longer among patients treated with vitamin C. In terms of patient safety, vitamin C has an acceptable profile. Low doses of vitamin C are effective and safe. Despite some evidence of the usefulness of vitamin C in modifying the course of COVID-19, it is too early to modify guidelines and recommendations. Further studies, in particular randomized clinical trials, are necessary.
Conflicts of Interest: The authors declare no conflict of interest.
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'abstract': '<jats:p>Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by the '
'severe respiratory syndrome coronavirus 2 (SARS-CoV-2), millions of people have died, and the '
'medical system has faced significant difficulties. Our purpose was to perform a meta-analysis '
'to estimate the effect of vitamin C on in-hospital mortality and the ICU or hospital length '
'of stay for patients diagnosed with COVID-19. We conducted a systematic review with '
'meta-analysis in the following databases: PubMed, Web of Science, Scopus and Cochrane Central '
'Register of Controlled Trials. We included studies that evaluated the effect of vitamin C '
'supplementation, compared with standard treatment in COVID-19 patients who are ≥18 y of age. '
'Nineteen trials were included in the meta-analysis. In-hospital mortality with and without '
'vitamin C supplementation was 24.1% vs. 33.9% (OR = 0.59; 95%CI: 0.37 to 0.95; p = 0.03), '
'respectively. Sub-analysis showed that, in randomized clinical trials, in-hospital mortality '
'varied and amounted to 23.9% vs. 35.8% (OR = 0.44; 95%CI: 0.25 to 0.76; p = 0.003), '
'respectively. In the non-randomized trials, in-hospital mortality was 24.2% vs. 33.5% (OR = '
'0.72; 95%CI: 0.38 to 1.39; p = 0.33), respectively. The ICU length of stay was longer in '
'patients treated with vitamin C vs. standard therapy, 11.1 (7.3) vs. 8.3 (4.7) days (MD = '
'1.91; 95%CI: 0.89 to 2.93; p < 0.001), respectively. Acute kidney injury in patients '
'treated with and without vitamin C varied and amounted to 27.8% vs. 45.0% (OR = 0.56; 95%CI: '
'0.40 to 0.78; p < 0.001), respectively. There were no differences in the frequency of '
'other adverse events among patients’ treatment with and without vitamin C (all p > 0.05). '
'The use of vitamin C reduces hospital mortality. The length of stay in the ICU is longer '
'among patients treated with vitamin C. In terms of patient safety, vitamin C has an '
'acceptable profile. Low doses of vitamin C are effective and safe. Despite some evidence of '
'the usefulness of vitamin C in modifying the course of COVID-19, it is too early to modify '
'guidelines and recommendations. Further studies, in particular randomized clinical trials, '
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'container-title': 'Nutrients',
'original-title': [],
'language': 'en',
'link': [ { 'URL': 'https://www.mdpi.com/2072-6643/14/19/4217/pdf',
'content-type': 'unspecified',
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'intended-application': 'similarity-checking'}],
'deposited': { 'date-parts': [[2022, 10, 11]],
'date-time': '2022-10-11T05:40:29Z',
'timestamp': 1665466829000},
'score': 1,
'resource': {'primary': {'URL': 'https://www.mdpi.com/2072-6643/14/19/4217'}},
'subtitle': [],
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'issued': {'date-parts': [[2022, 10, 10]]},
'references-count': 64,
'journal-issue': {'issue': '19', 'published-online': {'date-parts': [[2022, 10]]}},
'alternative-id': ['nu14194217'],
'URL': 'http://dx.doi.org/10.3390/nu14194217',
'relation': {},
'ISSN': ['2072-6643'],
'subject': ['Food Science', 'Nutrition and Dietetics'],
'container-title-short': 'Nutrients',
'published': {'date-parts': [[2022, 10, 10]]}}
