SynthesisNutrients2021
COVID-19 Mortality Risk Correlates Inversely with Vitamin D3 Status, and a Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3: Results of a Systematic Review and Meta-Analysis.
Synthesis in Nutrients, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers, 4 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
48 citing papers in PubMed, 4 syntheses or guidelines 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
- The Effects of Vitamin D Supplementation in COVID-19 Patients: A Systematic Review.International journal of molecular sciences · 2022Pooled it
- Pooled it
- Vitamin D Status and SARS-CoV-2 Infection and COVID-19 Clinical Outcomes.Frontiers in public health · 2021Pooled it
- Changes in the immune response against SARS-CoV-2 in individuals with severe COVID-19 treated with high dose of vitamin D.Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2022Trial
- Genetic Variants Influencing Individual Vitamin D Status.Nutrients · 2025Review
- Association between 25(OH)D levels and clinical outcomes in patients infected with SARS-CoV-2: a cross-sectional study.Scientific reports · 2025Article
- Vitamin D as an Adjuvant Immune Enhancer to SARS-Cov-2 Vaccine.Current microbiology · 2025Article
- Unveiling the Interplay-Vitamin D and ACE-2 Molecular Interactions in Mitigating Complications and Deaths from SARS-CoV-2.Biology · 2024Review
- Retrospective Analysis of the Effect of Postmenopausal Women Medications on SARS-CoV-2 Infection Progression.Life (Basel, Switzerland) · 2024Article
- Exploring the Therapeutic Potential of Vitamin D in Kawasaki Disease and Its Interplay with the COVID-19Turkish archives of pediatrics · 2024Article
- Physiology of Vitamin D-Focusing on Disease Prevention.Nutrients · 2024Review
- The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?Nutrients · 2024Review
- Impact of the COVID-19 lockdown on the vitamin D status of people in the West of Ireland.Irish journal of medical science · 2024Article
- Review
- Hospital Outcomes in Patients Hospitalized for COVID-19 Pneumonia: The Effect of SARS-CoV-2 Vaccination and Vitamin D Status.Nutrients · 2023Article
- Involvement of the secosteroid vitamin D in autoimmune rheumatic diseases and COVID-19.Nature reviews. Rheumatology · 2023Review
- The Role of Diet and Specific Nutrients during the COVID-19 Pandemic: What Have We Learned over the Last Three Years?International journal of environmental research and public health · 2023Review
- Article
- A Simultaneous Extraction/Derivatization Strategy for Quantitation of Vitamin D in Dried Blood Spots Using LC-MS/MS: Application to Biomarker Study in Subjects Tested for SARS-CoV-2.International journal of molecular sciences · 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
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundMuch research shows that blood calcidiol (25(OH)D3) levels correlate strongly with SARS-CoV-2 infection severity. There is open discussion regarding whether low D3 is caused by the infection or if deficiency negatively affects immune defense. The aim of this study was to collect further evidence on this topic.
methodsSystematic literature search was performed to identify retrospective cohort as well as clinical studies on COVID-19 mortality rates versus D3 blood levels. Mortality rates from clinical studies were corrected for age, sex, and diabetes. Data were analyzed using correlation and linear regression.
resultsOne population study and seven clinical studies were identified, which reported D3 blood levels preinfection or on the day of hospital admission. The two independent datasets showed a negative Pearson correlation of D3 levels and mortality risk (r(17) = -0.4154,
conclusionsThe datasets provide strong evidence that low D3 is a predictor rather than just a side effect of the infection. Despite ongoing vaccinations, we recommend raising serum 25(OH)D levels to above 50 ng/mL to prevent or mitigate new outbreaks due to escape mutations or decreasing antibody activity.
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.