Database of all vitamin D COVID-19 studies

Database of all vitamin D COVID-19 studies. Sufficiency studies analyze outcomes based on vitamin D levels, confounding factors may be significant. Treatment studies directly analyze the effect of vitamin D treatment. provides treatment recommendations. Submit updates/corrections.

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Dec 3

Early, Late, PrEP, PEPCovid Analysis (Preprint) (meta analysis)

meta-analysis v113

Vitamin D for COVID-19: real-time meta analysis of 143 studiesDetails • 85% of 53 vitamin D treatment studies report positive effects. 27 studies show statistically significant improvements in isolation (21 for the most serious outcome). • Random effects meta-analysis with pooled effects using the most ser..

Nov 30

LevelsFatemi et al., Acute and Critical Care, doi:10.4266/acc.2021.00605 (Peer Reviewed)

death, ↓42.0%, p=0.07

Association of vitamin D deficiency with COVID-19 severity and mortality in Iranian people: a prospective observational studyDetails Prospective study of 248 hospitalized COVID+ patients in Iran with vitamin D levels measured in the previous year and again at admission, showing vitamin D status associated with severity and mortality.

Nov 30

LevelsKaur et al., Indian Journal of Clinical Practice, 32:6 (Peer Reviewed)

death, ↓89.8%, p<0.0001

Correlation of Vitamin D Levels with COVID-19 Severity and OutcomeDetails Prospective study of 81 hospitalized COVID+ patients in India, showing low vitamin D levels associated with COVID-19 severity and mortality.

Nov 24

LevelsJenei et al., Clinical Nutrition ESPEN, doi:10.1016/j.clnesp.2021.11.025 (Peer Reviewed)COVID-19 mortality is associated with low Vitamin D levels in patients with risk factors and/or advanced ageDetails Retrospective 257 hospitalized patients in Hungary, showing mortality associated with lower vitamin D levels for all patients, for patients >60, and for age-matched patients with risk factors or age >60. The non-age-matched analyses are c..

Nov 12

LevelsSacristán et al., Transplantation Proceedings, doi:10.1016/j.transproceed.2021.08.060 (Peer Reviewed)Risk of severe COVID-19 infection in kidney transplant recipientsDetails Retrospective 63 COVID+ kidney transplant recipients, showing significantly lower vitamin D levels before infection in patients requiring ICU admission.

Nov 12

LevelsGönen et al., Nutrients, doi:10.3390/nu13114047 (Peer Reviewed)

death, ↓65.8%, p=0.62

Rapid and Effective Vitamin D Supplementation May Present Better Clinical Outcomes in COVID-19 (SARS-CoV-2) Patients by Altering Serum INOS1, IL1B, IFNg, Cathelicidin-LL37, and ICAM1Details Retrospective 867 hospitalized COVID-19 patients in Turkey, showing worse outcomes with vitamin D deficiency (without statistical significance); followed by a prospective study of 210 patients with vitamin D supplementation for those that..

Nov 10

LevelsAsghar et al., Am. J. Trop. Med. Hyg., doi:10.4269/ajtmh.21-0577 (Peer Reviewed)

death, ↓53.1%, p=0.05

Evaluation of Vitamin-D Status and Its Association with Clinical Outcomes Among COVID-19 Patients in PakistanDetails Retrospective 91 hospitalized patients in Pakistan, showing vitamin D deficiency associated with mortality in multivariate Cox regression.

Nov 3

LevelsGallelli et al., Nutrients, doi:10.3390/nu13113932 (Peer Reviewed)Vitamin D Serum Levels in Subjects Tested for SARS-CoV-2: What Are the Differences among Acute, Healed, and Negative COVID-19 Patients? A Multicenter Real-Practice StudyDetails Analysis of 117 patients in Italy, showing COVID-19 patients had significantly lower vitamin D levels than control patients.

Nov 2

LevelsAtanasovska et al., Redox Report, doi:10.1080/13510002.2021.1999126 (Peer Reviewed)

death, ↓40.7%, p=0.68

Vitamin D levels and oxidative stress markers in patients hospitalized with COVID-19Details Retrospective 33 COVID-19 hospitalized patients in North Macedonia, showing significantly lower vitamin D levels for severe vs. moderate cases. Oxidative stress was also higher for vitamin D insufficient patients.

Oct 25

LateLeal et al., SSRN, doi:10.2139/ssrn.3949424 (Preprint)

death, ↓85.7%, p=0.03

Effect of a Nutritional Support System to Increase Survival and Reduce Mortality in Patients with COVID-19 in Stage III and Comorbidities: A Blinded Randomized Controlled Clinical TrialDetails 80 patient RCT with 40 patients treated with a comprehensive regimen of nutritional support, showing significantly lower mortality with treatment. Treatment contained cholecalciferol, vitamin C, zinc, spirulina maxima, folic acid, glutam..

Oct 22

LevelsHurst et al., BMJ Open, doi:10.1136/bmjopen-2021-055435 (Peer Reviewed)

death, ↓68.4%, p=0.005

Vitamin D insufficiency in COVID-19 and influenza A, and critical illness survivors: a cross-sectional studyDetails Analysis of 259 hospitalized COVID-19 patients in the UK, showing a majority of patients had vitamin D deficiency/insufficiency, which was associated with poor outcomes. Both free and total 25(OH)D were analyzed with consistent results. I..

Oct 20

LevelsAl-Anouti et al., Nutrients, doi:10.3390/nu13113680 (Peer Reviewed)

severe case, ↓68.1%, p=0.0007

Associations between Genetic Variants in the Vitamin D Metabolism Pathway and Severity of COVID-19 among UAE ResidentsDetails Retrospective 646 COVID-19 patients in the UAE, showing significant associations between genetic determinants of vitamin D metabolism and COVID-19 severity, and an association with vitamin D deficiency and COVID-19 severity. Patients in t..

Oct 15

LevelsRamirez-Sandoval et al., Archives of Medical Research, doi:10.1016/j.arcmed.2021.09.006 (Peer Reviewed)

death, ↓31.5%, p<0.0001

Very Low Vitamin D Levels are a Strong Independent Predictor of Mortality in Hospitalized Patients with Severe COVID-19Details Retrospective 2,908 hospitalized patients in Mexico with vitamin D levels measured on admission, showing significantly lower mortality for patients without vitamin D deficiency.

Oct 13

LateMaghbooli et al., Endocrine Practice, doi:10.1016/j.eprac.2021.09.016 (Peer Reviewed)

death, ↓40.0%, p=0.72

Treatment with 25-hydroxyvitamin D3 (calcifediol) is associated with a reduction in the blood neutrophil-to-lymphocyte ratio marker of disease severity in patients hospitalized with COVID-19: a pilot, multicenter, randomized, placebo-controlled double blind clinical trialDetails RCT 106 hospitalized patients with vitamin D levels <30ng/ml in Iran, 53 treated with calcifediol, showing that treatment was able to correct vitamin D deficiency/insufficiency, resulting in improved immune system function. Hospitalizatio..

Oct 12

LevelsAfaghi et al., The Tohoku Journal of Experimental Medicine, doi:10.1620/tjem.255.127 (Peer Reviewed)

death, ↓55.0%, p=0.002

Prevalence and Clinical Outcomes of Vitamin D Deficiency in COVID-19 Hospitalized Patients: A Retrospective Single-Center AnalysisDetails Retrospective 646 COVID-19+ hospitalized patients in Iran, showing higher mortality with vitamin D deficiency.

Oct 12

PrEP, EarlyWorcel et al., Annals of Palliative Medicine, doi:10.21037/apm-21-1707 (Peer Reviewed)Low mortality from COVID-19 at a nursing facility in France following a combined preventive and active treatment protocolDetails Report on the relatively low mortality and relatively mild COVID-19 symptoms at a French nursing facility that has adopted several treatments including vitamin D, zinc, anticoagulants, corticosteroids, and a multivitamin.

Oct 9

LateCaballero-García et al., Medicina, doi:10.3390/medicina57101079 (Peer Reviewed)Effect of Vitamin D Supplementation on Muscle Status in Old Patients Recovering from COVID-19 InfectionDetails Small RCT with 30 patients examining the effect of vitamin D supplementation on muscle status in elderly recovering COVID-19 patients, showing serum creatine kinase levels returned to optimal values, however there was no significant diffe..

Oct 5

LevelsMukherjee et al., FEBS Open Bio, doi:10.1002/2211-5463.13309 (Peer Reviewed)Seasonal UV exposure and vitamin D: Association with the dynamics of COVID-19 transmission in EuropeDetails Analysis of UV and temperature levels in 26 European countries, showing that low temperature, UV index, and cloud-free vitamin D UV dose levels are negatively correlated with COVID-19 prevalence. Authors suggest that low UV exposure can a..

Oct 2

LevelsAbdollahzadeh et al., Infection, Genetics and Evolution, doi:10.1016/j.meegid.2021.105098 (Peer Reviewed)Association of Vitamin D receptor gene polymorphisms and clinical/severe outcomes of COVID-19 patientsDetails Analysis of 500 hospitalized patients in Iran, showing associations between specific vitamin D receceptor gene polymorphisms and COVID-19 outcomes.

Sep 27

LateYildiz et al., Bratislava Medical Journal, doi:10.4149/BLL_2021_119 (Peer Reviewed)

death, ↓80.9%, p=0.04

The prognostic significance of vitamin D deficiency in patients with COVID-19 pneumoniaDetails Retrospective 207 hospitalized patients in Turkey, 37 with vitamin D levels <30ng/ml treated with a 300,000IU vitamin D, showing lower mortality with treatment.

Sep 25

MetaBorsche et al., Nutrients, doi:10.3390/nu13103596 (preprint 9/25/2021) (Peer Reviewed) (meta analysis)


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-AnalysisDetails Meta analysis of 8 studies with vitamin D levels measured pre-infection or on the day of hospital admission, showing a correlation between the levels and mortality. Authors recommend combining vaccination with vitamin D supplementation to..

Sep 24

PrEPPEPArroyo-Díaz et al., Frontiers in Public Health, doi:10.3389/fpubh.2021.758347 (Peer Reviewed)

death, ↑12.4%, p=0.59

Previous Vitamin D Supplementation and Morbidity and Mortality Outcomes in People Hospitalised for COVID19: A Cross-Sectional StudyDetails Retrospective 1,267 hospitalized patients in Spain, 189 on vitamin D supplementation before admission, showing lower ICU admission with supplementation, and no statistically significant difference for mortality or ventilation.

Sep 22

ReviewCastle et al., Journal of Inflammation Research, doi:10.2147/JIR.S323356 (Review) (Peer Reviewed)


Implications for Systemic Approaches to COVID-19: Effect Sizes of Remdesivir, Tocilizumab, Melatonin, Vitamin D3, and MeditationDetails Review of the effects of COVID-19 on inflammatory markers, and the effects on those markers of standard treatments vs. vitamin D, melatonin, and meditation, showing comparable or superior effects with the non-standard treatments. The stan..

Sep 22

LevelsMarino-Ramirez et al., medRxiv, doi:10.1101/2021.09.20.21263865 (Preprint)Vitamin D and socioeconomic deprivation mediate COVID-19 ethnic health disparitiesDetails UK Biobank retrospective showing that vitamin supplements, including vitamin D, mediate the Asian disparity in COVID-19 susceptibility, and vitamin D levels mediate Asian and Black COVID-19 severity disparities. Authors conclude that the ..

Sep 19

LevelsDerakhshanian et al., Food Science & Nutrition, doi:10.1002/fsn3.2591 (Peer Reviewed)

death, ↓44.8%, p=0.05

The predictive power of serum vitamin D for poor outcomes in COVID-19 patientsDetails Retrospective 290 hospitalized patients in Iran, showing higher mortality with vitamin D deficiency.

Sep 14

LevelsPadhi et al., International Immunopharmacology, doi:10.1016/j.intimp.2020.107001 (Peer Reviewed)Lower levels of vitamin D are associated with SARS-CoV-2 infection and mortality in the Indian population: An observational studyDetails Analysis of vitamin D levels and COVID-19 in Indian states and union territories, showing an inverse correlation of vitamin D levels with SARS-CoV-2 cases and mortality.

Sep 9

In VitroPickard et al., PLOS Pathogens, doi:10.1371/journal.ppat.1009840 (Peer Reviewed) (In Vitro)

in vitro

Discovery of re-purposed drugs that slow SARS-CoV-2 replication in human cellsDetailsIn Vitro studying identifying 35 compounds that inhibit SARS-CoV-2 in Vero cells and hepatocytes when treated prior to infection, and several compounds that slow replication when treated after infection: vitamin D, amodiaquine, atovaquone..

Sep 8

LateElamir et al., Bone, doi:10.1016/j.bone.2021.116175 (Peer Reviewed)

death, ↓85.7%, p=0.23

A Randomized Pilot Study Using Calcitriol in Hospitalized PatientsDetails RCT 50 hospitalized patients in the USA, 25 treated with calcitriol, showing significantly improved oxygenation with treatment. Mortality, intubation, ICU admission, and hospitalization time also favored treatment, while not reaching stat..

Sep 5

PrEPPEPLázaro et al., Endocrine Abstracts, doi:10.1530/endoabs.70.EP552 (Preprint)

cases, ↓26.8%, p=1.00

Vitamin D deficit in type 2 diabetes patients during COVID-19 lockdown with and without supplementationDetails Analysis of 239 consecutive diabetic patients, 97 taking vitamin D supplements, showing significantly higher vitamin D levels in supplemented patients. There was no statistically significant difference in cases based on supplementation, w..

Sep 1

PrEPPEPBagheri et al., Journal of Family & Reproductive Health, doi:10.18502/jfrh.v14i3.4668 (Peer Reviewed)

progression, ↓70.9%, p=0.02

Supplement Usage Pattern in a Group of COVID- 19 Patients in TehranDetails Retrospective 510 patients in Iran, showing lower risk of severity with vitamin D (statistically significant) and zinc (not statistically significant) supplementation. IR.TUMS.VCR.REC.1398.1063.

Sep 1

LateSoliman et al., Proceedings of Singapore Healthcare, doi:10.1177/20101058211041405 (Peer Reviewed)

death, ↓63.4%, p=0.21

Impact of Vitamin D Therapy on the Progress COVID-19: Six Weeks Follow-Up Study of Vitamin D Deficient Elderly Diabetes PatientsDetails Small RCT with 56 eldery diabetes patients hospitalized in Egypt, 40 treated with cholecalciferol, not showing significant differences.

Aug 31

MetaBen-Eltriki et al., Journal of the American College of Nutrition, doi:10.1080/07315724.2021.1951891 (Peer Reviewed) (meta analysis)


Association between Vitamin D Status and Risk of Developing Severe COVID-19 Infection: A Meta-Analysis of Observational StudiesDetails Meta analysis of 24 observational studies with 3,637 participants, showing low vitamin D status associated with a higher risk of death and a higher risk of developing severe COVID-19 pneumonia.

Aug 29

LevelsKaronova et al., Nutrients, doi:10.3390/nu13093021 (Peer Reviewed)

death, ↓77.8%, p=0.006

Low 25(OH)D Level Is Associated with Severe Course and Poor Prognosis in COVID-19Details Retrospective 161 hospitalized patients in Russia, showing COVID-19 severity and mortality associated with vitamin D deficiency. Patients in this study may overlap with those in an earlier smaller study from some of the same authors.

Aug 28

LateAssiri et al., Journal of Infection and Public Health, doi:10.1016/j.jiph.2021.08.030 (Peer Reviewed)

death, ↑66.5%, p=0.60

COVID-19 related treatment and outcomes among COVID-19 ICU patients: A retrospective cohort studyDetails Retrospective 118 ICU patients in Saudi Arabia showing no significant differences in unadjusted results with zinc, vitamin D, and favipiravir treatment.

Aug 27

LevelsPecina et al., Journal of Primary Care & Community Health, doi:10.1177/21501327211041206 (Peer Reviewed)

death, ↓35.9%, p=0.74

Vitamin D Status and Severe COVID-19 Disease Outcomes in Hospitalized PatientsDetails Retrospective 92 hospitalized patients not showing significant differences in outcomes based on vitamin D status or supplementation.

Aug 26

PrEPPEPGolabi et al., Nutrients, doi:10.3390/nu13103368 (preprint 8/26/2021) (Peer Reviewed)

cases, ↑25.4%, p=0.56

The Association between Vitamin D and Zinc Status and the Progression of Clinical Symptoms among Outpatients Infected with SARS-CoV-2 and Potentially Non-Infected Participants: A Cross-Sectional StudyDetails Analysis of vitamin D and zinc levels in 53 PCR+ outpatients and 53 matched controls, showing lower zinc levels in COVID-19 patients, and increased risk of cases and symptoms with vitamin D deficiency. There was no significant difference ..

Aug 26

LevelsGolabi et al., Nutrients, doi:10.3390/nu13103368 (preprint 8/26/2021) (Peer Reviewed)

symp., ↓90.0%, p<0.0001

The Association between Vitamin D and Zinc Status and the Progression of Clinical Symptoms among Outpatients Infected with SARS-CoV-2 and Potentially Non-Infected Participants: A Cross-Sectional StudyDetails Analysis of vitamin D and zinc levels in 53 PCR+ outpatients and 53 matched controls, showing lower zinc levels in COVID-19 patients, and increased risk of cases and symptoms with vitamin D deficiency. There was no significant difference ..

Aug 25

MetaVarikasuvu (Preprint) (meta analysis)


COVID-19 and Vitamin D (Co-VIVID Study): a systematic review and meta-analysis of randomized controlled trialsDetails Meta analysis of 6 vitamin D treatment RCTs, showing statistically significant improvements for pooled outcomes and PCR positivity, and positive but not statistically significant improvements for mortality, mechanical ventilation, ICU adm..

Aug 20

In SilicoSong et al., Journal of Biomolecular Structure and Dynamics, doi:10.1080/07391102.2021.1964601 (Peer Reviewed)Vitamin D3 and its hydroxyderivatives as promising drugs against COVID-19: a computational studyDetailsIn Silico study suggesting that vitamin D3 and its biologically active hydroxyderivatives can serve as an TMPRSS2 inhibitor, and inhibit ACE2 binding with the SARS-CoV-2 RBD.

Aug 18

LevelsShakeri et al., Journal of Medical Virology, doi:10.1002/jmv.27277 (Peer Reviewed)Evaluation of the relationship between serum levels of zinc, vitamin B12, vitamin D, and clinical outcomes in patients with COVID-19Details Retrospective 293 hospitalized patients in Iran showing lower levels of zinc, vitamin B12, and vitamin D in patients that died, with statistical significance reached only for zinc.

Aug 12

Levelsdi Filippo et al, The Journal of Clinical Endocrinology & Metabolism, doi:10.1210/clinem/dgab599 (Peer Reviewed)

death, ↓10.7%, p=1.00

Vitamin D levels associate with blood glucose and BMI in COVID-19 patients predicting disease severityDetails Retrospective 88 patients in Italy, showing vitamin D deficiency associated with severe cases, blood glucose, and BMI.

Aug 11

LevelsSinaci et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2021.105964 (Peer Reviewed)

m/s case, ↓79.5%, p<0.0001

Impact of vitamin D on the course of COVID-19 during pregnancy: A case control studyDetails Retrospective 159 COVID-19+ pregnant women in Turkey and 332 healthy pregnant controls, showing significantly lower vitamin D levels in COVID-19+ patients. 23% of COVID-19 patients where on vitamin D supplementation, while none of the 7 s..

Aug 10

LevelsAlpcan et al., Epidemiology & Infection, doi:10.1017/S0950268821001825 (Peer Reviewed)

cases, ↓73.0%, p=0.0005

Vitamin D levels in children with COVID-19: a report from TurkeyDetails Retrospective 75 COVID-19 hospitalized pediatric patients in Turkey and 80 healthy controls, showing significantly lower vitamin D levels in COVID-19 patients.

Aug 5

LevelsEden et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000270 (Peer Reviewed)

death, ↓63.9%, p=0.10

Nutritional parameters and outcomes in patients admitted to intensive care with COVID-19: a retrospective single-centre service evaluationDetails Retrospective 72 ICU patients in the UK, showing higher mortality with vitamin D deficiency, not reaching statistical significance.

Aug 5

LevelsRibeiro et al., Clinica Chimica Acta, doi:10.1016/j.cca.2021.08.003 (Peer Reviewed)

cases, ↓50.5%, p=0.01

Previous vitamin D status and total cholesterol are associated with SARS-CoV-2 infectionDetails Retrospective 1,634 patients tested for SARS-CoV-2 in Brazil, showing vitamin D levels <30ng/mL associated with greater odds of a positive SARS-CoV-2 test in patients older than 49 years.

Aug 5

LevelsNimavat et al., Annals of Medicine and Surgery, doi:10.1016/j.amsu.2021.102661 (Peer Reviewed)

death, ↓50.4%, p=0.17

Vitamin D deficiency and COVID-19: A case-control study at a tertiary care hospital in IndiaDetails Case control study with 156 PCR+ cases in India and 204 controls, showing more frequent vitamin D deficiency in COVID-19 patients, and an association between lower vitamin D levels and COVID-19 severity.

Aug 4

PrEPPEPMohseni et al., Nutrition & Food Science, doi:10.1108/NFS-11-2020-0421 (Peer Reviewed)

cases, ↓12.4%, p=0.09

Do body mass index (BMI) and history of nutritional supplementation play a role in the severity of COVID-19? A retrospective studyDetails Retrospective 603 patients in Iran, 192 taking vitamin D supplements, showing no significant difference in COVID-19 cases in unadjusted results. IR.SHOUSHTAR.REC.1399.015.

Jul 30

LevelsMatin et al., Archives of Microbiology, doi:10.1007/s00203-021-02482-5 (Peer Reviewed)

cases, ↓66.1%, p<0.0001

The sufficient vitamin D and albumin level have a protective effect on COVID-19 infectionDetails Case control study with 191 COVID-19 patients and 203 healthy controls in Iran, showing an association between vitamin D deficiency and COVID-19 infection and severity. 84.4% of COVID-19 patients had vitamin D deficiency.

Jul 29

LevelsAl-Salman et al., Nutrition & Food Science, doi:10.1108/NFS-05-2021-0143 (Peer Reviewed)

ICU, ↓44.4%, p=0.03

In COVID-19 patients, low 25-hydroxyvitamin D level in serum is associated with longer viral clearance time and higher risk of intensive care unit admissionDetails Retrospective 450 hospitalized patients in Bahrain, showing increased risk of ICU admission and slower viral clearance with vitamin D deficiency.

Jul 29

MetaGhasemian et al., The International Journal of Clinical Practice, doi:10.1111/ijcp.14675 (Peer Reviewed) (meta analysis)


The Role of Vitamin D in the Age of COVID-19: A Systematic Review and Meta-AnalysisDetails Systematic review and meta analysis of 23 studies, finding significantly higher risk of COVID-19 cases and severity with vitamin D deficiency. Mortality risk was higher with deficiency, but not reaching statistical significance, OR 1.6 [0..

Jul 29

Early, PrEPAnnweiler et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:0.1016/j.jsbmb.2021.105958 (Peer Reviewed)

death, ↓64.2%, p=0.002

Vitamin D supplementation prior to or during COVID-19 associated with better 3-month survival in geriatric patients: Extension phase of the GERIA-COVID studyDetails Report on extended results from the GERIA-COVID study, showing significantly lower mortality at 3 months with vitamin D treatment. Results combine prophylaxis and early treatment.

Jul 27

In SilicoQayyum et al., Endocrinology and Metabolism, doi:10.1152/ajpendo.00174.2021 (Peer Reviewed)Vitamin D and lumisterol novel metabolites can inhibit SARS-CoV-2 replication machinery enzymesDetailsIn Silico analysis showing that vitamin D and lumisterol metabolites may inhibit SARS-CoV-2 Mpro and RdRP.