ReviewFrontiers in immunology2020
The Long History of Vitamin C: From Prevention of the Common Cold to Potential Aid in the Treatment of COVID-19.
Review in Frontiers in immunology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 86 papers, 6 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
86 citing papers in PubMed, 6 syntheses or guidelines pooled it.
- Pooled it
- Vitamin C reduces the severity of common colds: a meta-analysis.BMC public health · 2023Pooled it
- Vitamin C Supplementation for the Treatment of COVID-19: A Systematic Review and Meta-Analysis.Nutrients · 2022Pooled it
- Vitamins C and D and COVID-19 Susceptibility, Severity and Progression: An Evidence Based Systematic Review.Medicina (Kaunas, Lithuania) · 2022Pooled it
- The effectiveness of high-dose intravenous vitamin C for patients with coronavirus disease 2019: A systematic review and meta-analysis.Complementary therapies in medicine · 2022Pooled it
- Pooled it
- Vitamin C supplementation in patients with hypothyroidism requiring high-dose levothyroxine: a proof-of-concept pilot study.Frontiers in endocrinology · 2025Trial
- Safety and Tolerability of Multimodal Therapy (Ivermectin, Doxycycline, Vitamin C, Vitamin D, and Zinc) With or Without Famotidine in Australian Patients With COVID-19 Infection: A Pilot Cohort Trial.American journal of therapeuticsTrial
- Peri-weaning, diet-induced activation of an IFNγ-mediated regulatory circuit promotes cDC1 maturation and CD8Nature communications · 2026Article
- Reproductive and immune-related consequences ofFrontiers in veterinary science · 2026Article
- Market analysis of vitamin C-containing dietary supplements in Germany and the USA: Consumer information and risks and benefits.Naunyn-Schmiedeberg's archives of pharmacology · 2025Article
- Vitamin C in Pregnancy: A Key Modulator of Fetal Growth and Epigenetic Stability.Current nutrition reports · 2025Review
- Vitamin C in Allergy Mechanisms and for Managing Allergic Diseases: A Narrative Review.Children (Basel, Switzerland) · 2025Review
- Exploring the mechanism of vitamin C on the co-expressed genes of papillary thyroid carcinoma and Epstein-Barr virus based on bioinformatics, network pharmacology and molecular docking analysis.Discover oncology · 2025Article
- Nutrition Knowledge Varies by Food Group and Nutrient Among Adults.Foods (Basel, Switzerland) · 2025Article
- Vitamin C: A Comprehensive Review of Its Role in Health, Disease Prevention, and Therapeutic Potential.Molecules (Basel, Switzerland) · 2025Review
- Article
- Immune-Boosting and Antiviral Effects of Antioxidants in COVID-19 Pneumonia: A Therapeutic Perspective.Life (Basel, Switzerland) · 2025Review
- Herbal and Dietary Supplements as Adjunctive Treatment for Mild SARS-CoV-2 Infection in Italy.Nutrients · 2025Review
- The dynamic linkage between covid-19 and nutrition: a review from a probiotics perspective using machine learning and bibliometric analysis.Frontiers in nutrition · 2025Article
26 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
9 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
From Pauling's theories to the present, considerable understanding has been acquired of both the physiological role of vitamin C and of the impact of vitamin C supplementation on the health. Although it is well known that a balanced diet which satisfies the daily intake of vitamin C positively affects the immune system and reduces susceptibility to infections, available data do not support the theory that oral vitamin C supplements boost immunity. No current clinical recommendations support the possibility of significantly decreasing the risk of respiratory infections by using high-dose supplements of vitamin C in a well-nourished general population. Only in restricted subgroups (e.g., athletes or the military) and in subjects with a low plasma vitamin C concentration a supplementation may be justified. Furthermore, in categories at high risk of infection (i.e., the obese, diabetics, the elderly, etc.), a vitamin C supplementation can modulate inflammation, with potential positive effects on immune response to infections. The impact of an extra oral intake of vitamin C on the duration of a cold and the prevention or treatment of pneumonia is still questioned, while, based on critical illness studies, vitamin C infusion has recently been hypothesized as a treatment for COVID-19 hospitalized patients. In this review, we focused on the effects of vitamin C on immune function, summarizing the most relevant studies from the prevention and treatment of common respiratory diseases to the use of vitamin C in critical illness conditions, with the aim of clarifying its potential application during an acute SARS-CoV2 infection.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.