SynthesisNutrients2024
The Efficacy of Multivitamin, Vitamin A, Vitamin B, Vitamin C, and Vitamin D Supplements in the Prevention and Management of COVID-19 and Long-COVID: An Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Synthesis in Nutrients, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers, 1 of them a synthesis 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
25 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Efficacy of vitamin C in COVID-19 management: a systematic review and meta-analysis.BMC infectious diseases · 2025Pooled it
- Trial
- Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies.Current nutrition reports · 2026Review
- Integrated omics reveal the effects of vitamin D deficiency on gut microbiota and plasma metabolism in experimental autoimmune uveitis.Journal of neuroinflammation · 2026Article
- Impact of nutrition on long COVID.Sports medicine and health science · 2026Review
- Compact large language models for title and abstract screening in systematic reviews: An assessment of feasibility, accuracy, and workload reduction.Research synthesis methods · 2026Article
- Influence of lifestyle factors on susceptibility, disease course and recovery from post COVID-19 syndrome: a scoping review.BMJ public health · 2026Article
- Vitamin D neuroimmune synaptic plasticity and precision intervention in pediatric neurodevelopmental disorders.Frontiers in aging neuroscience · 2026Review
- Long COVID and gut microbiome: insights into pathogenesis and therapeutics.Gut microbes · 2025Review
- Long COVID: current research and future directions.Infectious diseases & immunity · 2025Review
- Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis.EClinicalMedicine · 2025Article
- Post-COVID Condition and Neuroinflammation: Possible Management with Antioxidants.Antioxidants (Basel, Switzerland) · 2025Review
- Dramatic Deterioration of Subclinical Hyperparathyroidism in Children and Adolescents During the Post-COVID-19 Period.Diseases (Basel, Switzerland) · 2025Article
- Therapeutic options for the treatment of post-acute sequelae of COVID-19: a scoping review.BMC infectious diseases · 2025Article
- Vitamin D Status and Incidence of SARS-CoV-2 Reinfections in the Borriana COVID-19 Cohort: A Population-Based Prospective Cohort Study.Tropical medicine and infectious disease · 2025Article
- Changes and clinical significance of serum vitamin A, 25-(OH)D3, TG2, IL-4 and IL-13 levels in children with eczema.Archives of dermatological research · 2025Article
- Role of intravenous vitamin C on outcomes in hospitalized patients with moderate or severe COVID-19: a real life data of Turkish patients.Inflammopharmacology · 2025Article
- Association of zinc deficiency and clinical symptoms, inflammatory markers, severity of COVID-19 in hospitalized children.Frontiers in nutrition · 2025Article
- Cardiovascular damage and comorbidities related to long COVID: pathomechanisms, prevention, and therapy.Frontiers in cardiovascular medicine · 2025Review
- Fitness and Dietary Supplements: A Cross-Sectional Study on Food Practices and Nutrivigilance.Nutrients · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
This review aims to evaluate the efficacy of any vitamin administration(s) in preventing and managing COVID-19 and/or long-COVID. Databases were searched up to May 2023 to identify randomized clinical trials comparing data on the effects of vitamin supplementation(s) versus placebo or standard of care on the two conditions of interest. Inverse-variance random-effects meta-analyses were conducted to estimate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for all-cause mortality between supplemented and non-supplemented individuals. Overall, 37 articles were included: two regarded COVID-19 and long-COVID prevention and 35 records the COVID-19 management. The effects of vitamin D in preventing COVID-19 and long-COVID were contrasting. Similarly, no conclusion could be drawn on the efficacy of multivitamins, vitamin A, and vitamin B in COVID-19 management. A few positive findings were reported in some vitamin C trials but results were inconsistent in most outcomes, excluding all-cause mortality (RR = 0.84; 95% CI: 0.72-0.97). Vitamin D results were mixed in most aspects, including mortality, in which benefits were observed in regular administrations only (RR = 0.67; 95% CI: 0.49-0.91). Despite some benefits, results were mostly contradictory. Variety in recruitment and treatment protocols might explain this heterogeneity. Better-designed studies are needed to clarify these vitamins' potential effects against SARS-CoV-2.
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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.