ReviewNutrients2017
Vitamin C and Infections.
Review in Nutrients, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 210 papers, 11 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
210 citing papers in PubMed, 11 syntheses or guidelines pooled it, 457 citations in OpenAlex.
- Pooled it
- Vitamin C reduces the severity of common colds: a meta-analysis.BMC public health · 2023Pooled it
- Select Dietary Supplement Ingredients for Preserving and Protecting the Immune System in Healthy Individuals: A Systematic Review.Nutrients · 2022Pooled it
- The Role and Efficacy of Vitamin C in Sepsis: A Systematic Review and Meta-Analysis.Advances in respiratory medicine · 2022Pooled it
- Vitamin C supplementation for prevention and treatment of pneumonia.The Cochrane database of systematic reviews · 2021Pooled it
- Nutritional perspectives for the prevention and mitigation of COVID-19.Nutrition reviews · 2021Pooled it
- Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.BMJ global health · 2021Pooled it
- Could Vitamins Help in the Fight Against COVID-19?Nutrients · 2020Pooled it
- Zinc Supplementation Reduces Common Cold Duration among Healthy Adults: A Systematic Review of Randomized Controlled Trials with Micronutrients Supplementation.The American journal of tropical medicine and hygiene · 2020Pooled it
- Vitamin C supplementation for prevention and treatment of pneumonia.The Cochrane database of systematic reviews · 2020Pooled it
- Effects of Vitamin C on Organ Function in Cardiac Surgery Patients: A Systematic Review and Meta-Analysis.Nutrients · 2019Pooled it
- Vitamin C supplementation in patients with hypothyroidism requiring high-dose levothyroxine: a proof-of-concept pilot study.Frontiers in endocrinology · 2025Trial
- Dietary supplements to reduce symptom severity and duration in people with SARS-CoV-2: a double-blind randomised controlled trial.BMJ open · 2023Trial
- Effect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical Trial.JAMA network open · 2021Trial
- The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older Adults: A Double-Blind, Randomized, Controlled Trial.Nutrients · 2020Trial
- The effect of β-carotene on the mortality of male smokers is modified by smoking and by vitamins C and E: evidence against a uniform effect of nutrient.Journal of nutritional science · 2020Trial
- Effect of Combined Polyphenol on the Disease Course in Children Diagnosed with Influenza.Pharmaceutics · 2026Article
- Chloroplasts as ingredients for food: a review.Food & function · 2026Review
- Are the UK's vitamin C recommendations evidence-based? A critical comment.The British journal of nutrition · 2026Review
- Vitamins in the Treatment of Periodontitis: Molecular Mechanism and Network Pharmacological Analysis.Oral health & preventive dentistry · 2025Review
150 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
1 author at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.