SynthesisQJM : monthly journal of the Association of Physicians2022
Does vitamin D supplementation reduce COVID-19 severity?: a systematic review.
Synthesis in QJM : monthly journal of the Association of Physicians, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 39 papers, 7 of them syntheses that pooled it.
What it found
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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.
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Who cites it
39 citing papers in PubMed, 7 syntheses or guidelines pooled it, 76 citations in OpenAlex.
- Effect of the vitamin D supplementation on clinical outcomes and inflammatory status in COVID-19 patients: an umbrella review.BMC nutrition · 2025Pooled it
- Pooled it
- Vitamin D Deficiency Meets Hill's Criteria for Causation in SARS-CoV-2 Susceptibility, Complications, and Mortality: A Systematic Review.Nutrients · 2025Pooled it
- Preventive Vitamin D Supplementation and Risk for COVID-19 Infection: A Systematic Review and Meta-Analysis.Nutrients · 2024Pooled it
- Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy.Inflammopharmacology · 2024Pooled it
- Pooled it
- Serum vitamin D levels and COVID-19 during pregnancy: A systematic review and meta-analysis.Clinical nutrition ESPEN · 2022Pooled it
- Trial
- Whey Proteins and Immunity: Mechanisms Underlying Immune System Reinforcement and Protection Against Viral and Bacterial Infections.Nutrients · 2026Review
- Vitamin D deficiency and disease conditions relevant to: Orthopaedic translation.Journal of orthopaedic translation · 2026Review
- Bridging Gaps in Long COVID Therapy: A Review.Current medicinal chemistry · 2026Review
- Association between vitamin D and COVID-19 infection and mortality in Taiwanese patients.Journal of the Chinese Medical Association : JCMA · 2025Article
- Demographic and Clinical Profile of Patients with Osteogenesis Imperfecta Hospitalized Due to Coronavirus Disease (COVID)-19: A Case Series of 13 Patients from Brazil.Healthcare (Basel, Switzerland) · 2025Article
- Vitamin D and COVID-19: Clinical Evidence and Immunological Insights.Life (Basel, Switzerland) · 2025Review
- The Impact of Vitamin D in the Prevention of Influenza, COVID-19, and Dengue: A Review.Biomedicines · 2025Review
- Exploring the Causal Effects of Micronutrient Supplementation on Susceptibility to Viral Pneumonia: A Mendelian Randomization Study.Pathogens (Basel, Switzerland) · 2025Article
- Protein swarm-based cause-effect analysis: effects of microRNAs on cooperation networks linking COVID-19 infections, atherosclerosis, and Alzheimer's disease.Frontiers in cardiovascular medicine · 2025Article
- Observational
- Retrospective Analysis of the Effect of Postmenopausal Women Medications on SARS-CoV-2 Infection Progression.Life (Basel, Switzerland) · 2024Article
- Evaluating the Impact of Vitamin DACS omega · 2024Article
Corrections and comments
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe evidence regarding the efficacy of vitamin D supplementation in reducing severity of COVID-19 is still insufficient. This is partially due to the lack of primary robust trial-based data and heterogeneous study designs.
aimThis evidence summary, aims to study the effect of vitamin D supplementation on morbidity and mortality in hospitalized COVID-19 patients.Design: Evidence summary of systematic reviews.
methodsFor this study, systematic reviews and meta-analysis published from December 2019 to January 2022 presenting the impact of vitamin D supplementation on COVID-19 severity were screened and selected from PubMed and Google scholar. After initial screening, 10 eligible reviews were identified and quality of included reviews were assessed using AMSTAR and GRADE tools and overlapping among the primary studies used were also assessed.
resultsThe number of primary studies included in the systematic reviews ranged from 3 to 13. Meta-analysis of seven systematic reviews showed strong evidence that vitamin D supplementation reduces the risk of mortality (Odds ratio: 0.48, 95% CI: 0.346-0.664; P < 0.001) in COVID patients. It was also observed that supplementation reduces the need for intensive care (Odds ratio: 0.35; 95%CI: 0.28-0.44; P < 0.001) and mechanical ventilation (Odds ratio: 0.54; 95% CI: 0.411-0.708; P < 0.001) requirement. The findings were robust and reliable as level of heterogeneity was considerably low. However the included studies were of varied quality. Qualitative analysis showed that supplements (oral and IV) are well tolerated, safe and effective in COVID patients.
conclusionThe findings of this study show that vitamin D supplementation is effective in reducing the COVID-19 severity. Hence, vitamin D should be recommended as an adjuvant therapy for COVID-19.However, more robust and larger trials are required to substantiate it further.
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