Observational studyNutrients2021
Vitamin A Plasma Levels in COVID-19 Patients: A Prospective Multicenter Study and Hypothesis.
Observational study in Nutrients, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 44 papers, 2 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
44 citing papers in PubMed, 2 syntheses or guidelines pooled it, 80 citations in OpenAlex.
- The Association Between Antioxidants and COVID-19 Outcomes: a Systematic Review on Observational Studies.Biological trace element research · 2023Pooled it
- Identification of Parameters Representative of Immune Dysfunction in Patients with Severe and Fatal COVID-19 Infection: a Systematic Review and Meta-analysis.Clinical reviews in allergy & immunology · 2023Pooled it
- Enhanced stability and clinical absorption of a form of encapsulated vitamin A for food fortification.Proceedings of the National Academy of Sciences of the United States of America · 2022Trial
- All-trans retinoic acid suppresses systemic inflammation induced by severe fever with thrombocytopenia syndrome virus in mice.Nature microbiology · 2026Article
- Vitamins impacting mental/physical well-being during viral pandemics: a mechanistic review based on COVID-19: a comprehensive review.Inflammopharmacology · 2026Review
- The mechanisms underlying COVID-19 induced insulin resistance: a narrative review.Frontiers in endocrinology · 2026Review
- Medication, Nutrition, and Hygiene in COVID-19 Prevention and Treatment: A Comprehensive Narrative Review.Global challenges (Hoboken, NJ) · 2025Review
- Vitamin A and Its Related Diseases.Food science & nutrition · 2025Review
- Exploring the link between fat-soluble vitamins and aging-associated immune system status: a literature review.Immunity & ageing : I & A · 2025Review
- Immune-Boosting and Antiviral Effects of Antioxidants in COVID-19 Pneumonia: A Therapeutic Perspective.Life (Basel, Switzerland) · 2025Review
- Cardiovascular damage and comorbidities related to long COVID: pathomechanisms, prevention, and therapy.Frontiers in cardiovascular medicine · 2025Review
- Association Between Vitamin A and D Status and the Risk of COVID-19 in the Elderly Population: A Single-Center Experience.Journal of inflammation research · 2025Article
- What do we know about micronutrients in critically ill patients? A narrative review.JPEN. Journal of parenteral and enteral nutrition · 2025Review
- The Role of Vitamins, Magnesium, and Trace Elements in COVID-19 Treatment and Post-COVID-19 Rehabilitation: An Updated Overview.Current medicinal chemistry · 2025Review
- Gene expression profiles in COVID-19-associated tracheal stenosis indicate persistent anti-viral response and dysregulated retinol metabolism.BMC research notes · 2024Article
- Retinol and retinol binding protein 4 levels and COVID-19: a Mendelian randomization study.BMC pulmonary medicine · 2024Article
- Article
- Vitamin A Positively Correlates with Secretory Immunoglobulin A: A Cross-Sectional Study in Omicron COVID-19 Outpatients.Journal of clinical medicine · 2024Article
- Article
- Retinol Levels and Severity of Patients with COVID-19.Nutrients · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
COVID-19 is a pandemic disease that causes severe pulmonary damage and hyperinflammation. Vitamin A is a crucial factor in the development of immune functions and is known to be reduced in cases of acute inflammation. This prospective, multicenter observational cross-sectional study analyzed vitamin A plasma levels in SARS-CoV-2 infected individuals, and 40 hospitalized patients were included. Of these, 22 developed critical disease (Acute Respiratory Distress Syndrome [ARDS]/Extracorporeal membrane oxygenation [ECMO]), 9 developed severe disease (oxygen supplementation), and 9 developed moderate disease (no oxygen supplementation). A total of 47 age-matched convalescent persons that had been earlier infected with SARS-CoV-2 were included as the control group. Vitamin A plasma levels were determined by high-performance liquid chromatography. Reduced vitamin A plasma levels correlated significantly with increased levels of inflammatory markers (CRP, ferritin) and with markers of acute SARS-CoV-2 infection (reduced lymphocyte count, LDH). Vitamin A levels were significantly lower in hospitalized patients than in convalescent persons (
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.