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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. Submit updates/corrections below. provides treatment recommendations. To join a vitamin D trial in the US see
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Early, Late, PrEP, PEP Covid Analysis (Preprint) (meta analysis) meta-analysis v77 Vitamin D for COVID-19: real-time meta analysis of 97 studies
Details   • 91% of 33 vitamin D treatment studies report positive effects (17 statistically significant in isolation). • Random effects meta-analysis with pooled effects using the most serious outcome reported shows 80% and 42% improvement for
Levels Matin 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 infection
Details   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.
Meta Ghasemian et al., The International Journal of Clinical Practice, doi:10.1111/ijcp.14675 (Peer Reviewed) (meta analysis) meta-analysis The Role of Vitamin D in the Age of COVID-19: A Systematic Review and Meta-Analysis
Details   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..
Early, PrEP Annweiler 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 study
Details   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.
Levels Cozier et al., PLoS ONE, doi:10.1371/journal.pone.0255132 (Peer Reviewed) cases, ↓38.6%, p=0.02 Lower serum 25(OH)D levels associated with higher risk of COVID-19 infection in U.S. Black women
Details   Prospective study of vitamin D levels and COVID-19 infection in the Black Women's Health Study, showing higher risk of infection for lower vitamin D levels. Vitamin D levels were from 3-7 years before infection. Levels at the time of infe..
PrEP Israel et al., Epidemiology and Global Health Microbiology and Infectious Disease, doi:10.7554/eLife.68165 (Peer Reviewed) hosp., ↓9.1%, p=0.003 Identification of drugs associated with reduced severity of COVID-19: A case-control study in a large population
Details   Case control study examining medication usage with a healthcare database in Israel, showing lower risk of hospitalization with vitamin D (defined as being picked up within 35 days prior to PCR+). Other patients may have acquired vitamin D..
Late Güven et al, European Journal of Clinical Nutrition, doi:10.1038/s41430-021-00984-5 (Peer Reviewed) death, ↓24.8%, p=0.32 The effect of high-dose parenteral vitamin D3 on COVID-19-related inhospital mortality in critical COVID-19 patients during intensive care unit admission: an observational cohort study
Details   Retrospective 175 ICU patients, 113 treated with a single dose of 300,000IU intramuscular cholecalciferol, showing lower mortality with treatment, but not reaching statistical significance. Calcifediol or calcitriol, which avoids several ..
PrEP Oristrell et al., Journal of Endocrinological Investigation, doi:10.1007/s40618-021-01639-9 (Peer Reviewed) death, ↑1.0%, p=0.91 Vitamin D supplementation and COVID-19 risk: a population-based, cohort study
Details   Retrospective study of cholecalciferol and calcitriol supplementation in Catalonia showing a small but significant lower risk of cases with cholecalciferol, but no significant difference for mortality, or for calcitriol supplementation. S..
Late Sabico et al., Nutrients, doi:10.3390/nu13072170 (Peer Reviewed) Effects of a 2-Week 5000 IU versus 1000 IU Vitamin D3 Supplementation on Recovery of Symptoms in Patients with Mild to Moderate Covid-19: A Randomized Clinical Trial
Details   Small RCT of 69 hospitalized patients comparing 1000IU and 5000IU daily cholecalciferol, showing faster recovery with the higher dose.
Meta Pal et al., Journal of Endocrinological Investigation, doi:10.1007/s40618-021-01614-4 (Peer Reviewed) (meta analysis) meta-analysis Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis
Details   Meta analysis of 13 vitamin D treatment studies, showing significantly lower ICU admission/mortality with treatment.
Levels Jude et al., Journal of Clinical Endocrinology & Metabolism, doi:10.1210/clinem/dgab439 (Peer Reviewed) hosp., ↓71.6%, p<0.0001 Vitamin D deficiency is associated with higher hospitalisation risk from COVID-19: a retrospective case-control study
Details   Retrospective 80,670 people in the UK with vitamin D levels measured within the last 12 months, showing higher risk of hospitalization with low vitamin D levels.
Levels Campi et al., BMC Infectious Diseases, doi:10.1186/s12879-021-06281-7 (Peer Reviewed) death, ↓24.3%, p=0.53 Vitamin D and COVID-19 severity and related mortality: a prospective study in Italy
Details   Prospective study of 103 hospitalized patients in Italy, showing very high prevalence of vitamin D deficiency, and increased severity for lower vitamin D levels.
Levels Dror et al., medRxiv, doi:10.1101/2021.06.04.21258358 (Preprint) severe case, ↓85.1%, p<0.0001 Pre-infection 25-hydroxyvitamin D3 levels and association with severity of COVID-19 illness
Details   Retrospective 253 hospitalized patients in Israel showing higher mortality and higher risk of severe cases with vitamin D deficiency. Vitamin D levels were measured 14 to 730 days before the COVID-19 test. Adjusted results are only provid..
Levels Diaz-Curiel, Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2021.105928 (Peer Reviewed) ICU, ↓73.2%, p=0.02 The relationship between 25(OH) vitamin D levels and COVID-19 onset and disease course in Spanish patients
Details   Retrospective 1,549 patients in Spain showing that the frequency of vitamin D deficiency was higher in admitted patients compared to the overall Spanish population, and that vitamin D deficiency was associated with increased risk of ICU a..
Levels Kotur et al., Frontiers in Nutrition, doi:10.3389/fnut.2021.689419 (Peer Reviewed) Association of Vitamin D, Zinc and Selenium Related Genetic Variants With COVID-19 Disease Severity
Details   Analysis of variants in genes significant for the status of vitamin D in 120 Serbian COVID-19 patients, showing that vitamin D related genetic variants DHCR7/NADSYN rs12785878 and CYP2R1 rs10741657 were associated with severe COVID-19 in ..
PrEP Fasano et al., Movement Disorders, doi:10.1002/mds.28176 (Peer Reviewed) cases, ↓42.0%, p=0.05 COVID-19 in Parkinson’s Disease Patients Living in Lombardy, Italy
Details   Retrospective phone survey of 1,486 Parkinson's disease patients in Italy, showing lower risk of COVID-19 cases with vitamin D supplementation. This paper also presents a case control study of PD patients and family member control patients.
Levels Butler-Laporte et al., PLOS Medicine, doi:10.1371/journal.pmed.1003605 (Peer Reviewed) Vitamin D and COVID-19 susceptibility and severity in the COVID-19 Host Genetics Initiative: A Mendelian randomization study
Details   Mendelian randomization study not finding significant differences in COVID-19 outcomes based on vitamin D level. This study does not compare patients with deficiency/insuffiency/sufficiency, only providing ORs for increase in D levels. Au..
Levels Pimental et al., Clinical Nutrition ESPEN, doi:10.1016/j.clnesp.2021.05.021 (Peer Reviewed) death, ↓29.4%, p=1.00 Low vitamin D levels and increased neutrophil in patients admitted at ICU with COVID-19
Details   Retrospective 25 ICU patients in Brazil, showing vitamin D deficiency associated with higher neutrophil-lymphocyte ratio. There appears to be a typo in the mortality percentage for vitamin D deficiency (20% is not valid for the group size..
Levels Sooriyaarachchi et al., Clinical Nutrition ESPEN, doi:10.1016/j.clnesp.2021.05.011 (Peer Reviewed) Impact of vitamin D deficiency on COVID-19
Details   Analysis of vitamin D deficiency and COVID-19 cases and deaths in 47 countries, showing vitamin D deficiency significantly associated with mortality.
Early Sánchez-Zuno, J. Clinical Medicine, doi:10.3390/jcm10112378 (Peer Reviewed) severe case, ↓89.4%, p=0.04 Vitamin D Levels in COVID-19 Outpatients from Western Mexico: Clinical Correlation and Effect of Its Supplementation
Details   Very small 42 PCR+ outpatient RCT in Mexico, 22 treated with vitamin D. Most patients had insufficient vitamin D levels, there were more symptoms in those with insufficient levels, and there were less cases with fever or with >3 symptoms ..
In Silico Al-Mazaideh et al., Journal of Pharmaceutical Research International, doi:10.9734/jpri/2021/v33i29B31603 (Peer Reviewed) Vitamin D is a New Promising Inhibitor to the Main Protease (Mpro) of COVID-19 by Molecular Docking
Details   In Silico study showing vitamin D binding with Mpro of SARS-CoV-2. Among the compounds tested, vitamin D had the highest potential interaction in terms of total H-bond, van der Waal, torsional, and desolvation energy. Authors recommend ad..
Levels Papadimitriou et al., World J. Virology, doi:10.5501/wjv.v10.i3.111] (Peer Reviewed) Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach
Details   Country analysis showing negative correlations between population vitamin D level and severe cases and death (but not with cases overall). Authors conclude that higher vitamin D levels may protect from severe cases and death, even more so..
Early Asimi et al., Endocrine Abstracts, doi:10.1530/endoabs.73.PEP14.2 (Preprint) ventilation, ↓97.4%, p<0.0001 Selenium, zinc, and vitamin D supplementation affect the clinical course of COVID-19 infection in Hashimoto’s thyroiditis
Details   Retrospective 356 Hashimoto's thyroiditis outpatients, 270 taking vitamin D, zinc, and selenium, showing significantly lower hospitalization with treatment. Authors adjust for age, gender, BMI, and smoking status, reporting statistically ..
Late Alcala-Diaz et al., Nutrients, doi:10.3390/nu13061760 (Peer Reviewed) death, ↓80.8%, p=0.02 Calcifediol Treatment and Hospital Mortality Due to COVID-19: A Cohort Study
Details   Retrospective 537 patients in Spain, 79 treated with calcifediol, showing significantly lower mortality with treatment. The treated group had a higher risk of comorbidity, whereas the control group had lower O2 saturation, higher CURB‐65,..
Levels AlSafar et al., Nutrients, doi:10.3390/nu13051714 (Peer Reviewed) death, ↓59.3%, p=0.05 COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents
Details   Retrospective 464 patients in United Arab Emirates showing low D levels at first hospital visit associated with higher COVID-19 severity and mortality.
Levels Li et al., JAMA Network Open, doi:10.1001/jamanetworkopen.2021.11634 (Peer Reviewed) cases, ↓8.6%, p=0.21 Assessment of the Association of Vitamin D Level With SARS-CoV-2 Seropositivity Among Working-Age Adults
Details   Cohort study of 18,148 patients in the USA showing low vitamin D associated with COVID-19 PCR+ status before adjustments but not after. Authors state that "low vitamin D levels were not independently associated with the risk of sero..
Levels Savitri et al., Annals of the Romanian Society for Cell Biology, 25:6 (Peer Reviewed) symp. case, ↓88.0%, p<0.0001 Comparison between Vitamin D Level of Asymptomatic Confirmed Covid-19 Patients with Symptomatic Confirmed Covid-19 Patients in Makassar
Details   Retrospective 42 PCR+ patients in Indonesia, showing significantly higher risk of symptomatic cases with vitamin D deficiency.
PrEP Levitus et al., Journal of the Endocrine Society, doi: 10.1210/jendso/bvab048.567 (Peer Reviewed) severe case, ↓30.8%, p=0.25 The Effect of Vitamin D Supplementation on Severe COVID-19 Outcomes in Patients With Vitamin D Insufficiency
Details   Retrospective 129 hospitalized patients with vitamin D levels measured within 90 days prior to admission, showing lower, but not statistically significant, risk of severe cases with vitamin D supplementation among patients with levels <20..
Early Loucera et al., medRxiv, doi:10.1101/2021.04.27.21255937 (Preprint) death, ↓71.9%, p<0.0001 Real world evidence of calcifediol use and mortality rate of COVID-19 hospitalized in a large cohort of 16,401 Andalusian patients
Details   Retrospective 16,401 hospitalized patients in Spain showing a significant reduction in mortality associated with the prescription of vitamin D, especially calcifediol, within 15-30 days prior to hospitalization.
Levels Al-Daghri et al., Journal of Translational Medicine, doi:10.1186/s12967-021-02838-x (Peer Reviewed) Vitamin D status of Arab Gulf residents screened for SARS-CoV-2 and its association with COVID-19 infection: a multi-centre case–control study
Details   Case control study with 220 adults showing significantly lower vitamin D levels in PCR+ patients.
Review Shah Alam et al., International Immunopharmacology, doi:10.1016/j.intimp.2021.107686 (Review) (Peer Reviewed) review The role of vitamin D in reducing SARS-CoV-2 infection: An update
Details   Review of vitamin D for COVID-19 noting that infections are likely to be more prevalent in the winter season; clinical trials show vitamin D as a potential therapeutic agent; vitamin D is beneficial against COVID-19 by reducing inflammato..
PrEP Oristrell et al., Biomedicines, doi:10.3390/biomedicines9050509 (preprint 4/6/21) (Peer Reviewed) death, ↓43.0%, p=0.001 Association of Calcitriol Supplementation with Reduced COVID-19 Mortality in Patients with Chronic Kidney Disease: A Population-based Study
Details   Retrospective study of calcitriol supplementation with chronic kidney disease patients in Catalonia showing lower cases, severe cases, and mortality with supplementation. A dose-response relationship was found for severe cases and mortali..
Levels Ünsal et al., Journal of Endocrinological Investigation, doi:10.1007/s40618-021-01566-9 (Peer Reviewed) death, ↓80.6%, p=0.23 Retrospective analysis of vitamin D status on ınflammatory markers and course of the disease in patients with COVID-19 infection
Details   Retrospective 56 patients in Turkey showing greater need for oxygen therapy and higher mortality with vitamin D deficiency, and significantly lower risk of pneumonia with vitamin D supplementation.
Levels Livingston et al., Int. J. Clinical Practive, doi:10.1111/ijcp.14166 (Peer Reviewed) cases, ↓50.9%, p<0.0001 Detectable respiratory SARS‐CoV‐2 RNA is associated with low vitamin D levels and high social deprivation
Details   Retrospective 104 consecutive patients tested for COVID-19 in a hospital in the UK, showing lower vitamin D and higher social deprivation associated with COVID-19 positive results.
Levels Bayramoğlu et al., European Journal of Pediatrics, doi:10.1007/s00431-021-04030-1 (Peer Reviewed) severe case, ↓69.5%, p=0.0008 The association between vitamin D levels and the clinical severity and inflammation markers in pediatric COVID-19 patients: single-center experience from a pandemic hospital
Details   Retrospective 103 pediatric hospitalized COVID-19 patients, showing an association between vitamin D deficiency and clinical severity.
Meta Akbar et al., Front. Nutr. 8:660420, doi:10.3389/fnut.2021.660420 (Peer Reviewed) (meta analysis) meta-analysis Low Serum 25-hydroxyvitamin D (Vitamin D) Level Is Associated With Susceptibility to COVID-19, Severity, and Mortality: A Systematic Review and Meta-Analysis
Details   Systematic review and meta analysis showing that low vitamin D levels was associated with COVID-19 cases, severity, and mortality.
Levels Freitas et al., medRxiv, doi:10.1101/2021.03.22.21254032 (Preprint) death, ↓41.2%, p=0.02 Vitamin D-related polymorphisms and vitamin D levels as risk biomarkers of COVID-19 infection severity
Details   Analysis of 491 hospitalized patients in Portugal showing that polymorphisms in the vitamin D binding protein encoded by the GC gene are related to COVID-19 severity (p = 0.005). There was an association between vitamin D polygenic risk s..
Meta Petrelli et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2021.105883 (Peer Reviewed) (meta analysis) meta-analysis Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies
Details   Meta analysis showing vitamin D deficiency associated with higher risk of COVID-19, worse severity, and higher mortality. Supplementation with vitamin D reduced the risk of severe cases and mortality.
Review Kohlmeier et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000265 (Review) (Peer Reviewed) review When Mendelian randomisation fails
Details   Analysis of why Mendelian randomization may fail in vitamin D studies. Authors suggest that it may come down to the use of 25-OHD concentration in serum as a less than ideal proxy for vitamin D status of cells involved in the immune respo..
Levels Meltzer et al., JAMA Netw Open., doi:10.1001/jamanetworkopen.2021.4117 (Peer Reviewed) cases, ↓34.6%, p=0.11 Association of Vitamin D Levels, Race/Ethnicity, and Clinical Characteristics With COVID-19 Test Results
Details   Retrospective 4,638 individuals with vitamin D levels within 1 year before COVID-19 testing, showing higher risk of COVID-19 PCR+ for vitamin D deficient individuals, and lower (but not statistically significant) cases for individuals usi..
Levels Vanegas-Cedillo, medRxiv, doi:10.1101/2021.03.12.21253490 (Preprint) death, ↓52.6%, p=0.006 Serum Vitamin D levels are associated with increased COVID-19 severity markers and mortality independent of visceral adiposity
Details   Retrospective 551 moderate to severe COVID-19 patients in Mexico showing vitamin D ≤12ng/mL independently associated with COVID-19 mortality. No association was found between vitamin D levels and the need for intubation. Vitamin D deficie..
Levels Jayawardena et al., Diabetes & Metabolic Syndrome: Clinical Research & Reviews, doi:10.1016/j.dsx.2021.03.006 (Peer Reviewed) Impact of the vitamin D deficiency on COVID-19 infection and mortality in Asian countries
Details   Analysis of Asian countries finding that prevalence of vitamin D deficiency and lower vitamin D levels were associated with COVID-19 infection and mortality. Positive correlations were observed for prevalence of vitamin D deficiency with..
Levels Ahmad et al., medRxiv, doi:10.1101/2021.03.11.21253361 (Preprint) death, ↓53.6%, p=0.03 Mean Vitamin D levels in 19 European Countries & COVID-19 Mortality over 10 months
Details   Retrospective 19 European countries showing countries with mean vitamin D levels > 50nmol/L have a 2.2 times lower risk of mortality (p = 0.032) compared to those with mean levels < 50 nmol/L.
Levels Charoenngam et al., Endocrine Practice, doi:10.1016/j.eprac.2021.02.013 (Peer Reviewed) death, ↓34.1%, p=0.19 Association of vitamin D status with hospital morbidity and mortality in adult hospitalized COVID-19 patients
Details   Retrospective 287 hospitalized patients in the USA showing significantly lower mortality with vitamin D sufficiency in elderly patients and patients without obesity; and lower mortality for all patients but not reaching statistical signif..
Late Notz et al., Clinical Nutrition, doi:10.1016/j.clnu.2021.03.001 (Peer Reviewed) Vitamin D deficiency in critically ill COVID-19 ARDS patients
Details   Retrospective 26 ICU patients showing that the majority of patients had vitamin D deficiency. There was no statistically significant association of 25-hydroxyvitamin D status and clinical course, however low levels of 1,25-dihydroxyvitami..
Levels Kralj et al., Critical Case Reports, doi:10.1002/ccr3.4010 (Peer Reviewed) Vitamin D and COVID‐19 in an immunocompromised patient with multiple comorbidities—A Case Report
Details   Case report of a high-risk immunocompromised patient with multiple comorbidities that had a mild case of COVID-19. The patient had UVB phototherapy three months earlier and had normal vitamin D levels (92.2 nmol/L, normal range 50-125).
Levels Mazziotti et al., J Endocrinol. Invest., doi:10.1007/s40618-021-01535-2 (Peer Reviewed) progression, ↓37.0%, p=0.006 Vitamin D deficiency, secondary hyperparathyroidism and respiratory insufficiency in hospitalized patients with COVID-19
Details   Retrospective 348 hospitalized patients in Italy showing vitamin D deficiency associated with acute hypoxemic respiratory failure.
Levels Lohia et al., American Journal of Physiology-Endocrinology and Metabolism, doi:10.1152/ajpendo.00517.2020 (Peer Reviewed) death, ↓14.7%, p=0.56 Exploring the link between vitamin D and clinical outcomes in COVID-19
Levels Ricci et al., Respiratory Research, doi:10.1186/s12931-021-01666-3 (Peer Reviewed) death, ↓87.6%, p=0.07 Circulating Vitamin D levels status and clinical prognostic indices in COVID-19 patients
Details   Retrospective 52 hospitalized COVID-19 patients showing that vitamin D deficiency is associated with compromised inflammatory responses and higher pulmonary involvement. Vitamin D deficient patients also showed higher mortality, although ..
PrEP Sulli et al., Nutrients, doi:10.3390/nu13030717 (Peer Reviewed) cases, ↓50.4%, p=0.0002 Vitamin D and Lung Outcomes in Elderly COVID-19 Patients
Details   Retrospective 65 elderly COVID-19 patients and 65 matched controls, showing lower vitamin D levels associated with more severe lung involvement, longer disease duration, and higher mortality. Vitamin D supplementation was less common in t..
Late Lakkireddy et al., Scientific Reports, doi:10.1038/s41598-021-90189-4 (preprint 2/23/21) (Peer Reviewed) death, ↓60.9%, p=0.27 Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease
Details   RCT 44 treatment and 43 control patients with vitamin D levels <30ng/ml, showing significant reduction in inflammatory markers with treatment of 60,000IU vitamin D per day for 8 days (10 days for BMI >25). Death and ICU admission was lowe..
Levels Gavioli et al., Journal of the American College of Nutrition, doi:10.1080/07315724.2020.1869626 (Peer Reviewed) death, ↑4.7%, p=0.83 An Evaluation of Serum 25-Hydroxy Vitamin D Levels in Patients with COVID-19 in New York City
Details   Retrospective 437 mostly serious condition (85% hospitalized) patients in New York, showing vitamin D deficiency associated with increased likelihood of oxygen support, but no association with mortality and hospitalization. Multivariate a..
Levels Infante et al., Journal of the American College of Nutrition, doi:10.1080/07315724.2021.1877580 (Peer Reviewed) death, ↓54.8%, p=0.05 Low Vitamin D Status at Admission as a Risk Factor for Poor Survival in Hospitalized Patients With COVID-19: An Italian Retrospective Study
Details   Retrospective 137 hospitalized patients in Italy. All patients had low vitamin D levels, and lower levels were associated with higher mortality. In multivariate logistic regression, vitamin D levels were significantly inversely associate..
Levels Susianti et al., Journal of Medical Biochemistry, doi:10.5937/jomb0-30228 (Peer Reviewed) death, ↓91.5%, p=0.32 Low Levels of Vitamin D were Associated with Coagulopathy among Hospitalized Coronavirus Disease-19 (COVID-19) Patient: a Single Centered Study in Indonesia
Details   Retrospective 50 hospitalized PCR+ patients in Indonesia showing ICU admission, mortality, and ISTH DIC (Disseminated Intravascular Coagulation) score>=5, and increased D-dimer significantly associated with lower vitamin D levels.
Levels Yadav et al., Indian Journal of Clinical Biochemistry, doi:10.1007/s12291-020-00950-1 (Peer Reviewed) Association of Vitamin D Status with COVID-19 Infection and Mortality in the Asia Pacific region: A Cross-Sectional Study
Details   Analysis of vitamin D levels and COVID-19 in 37 Asia Pacific countries, finding a significant association with the number of cases/million (r =  −0.394, p = 0.016) and a weak association with the number of deaths/ million (r =  −0.280, p ..
Levels Söbü et al., The Journal of Current Pediatrics, doi:10.4274/jcp.2021.0002 (Peer Reviewed) Vitamin D Levels of COVID-19 Positive Sypmtomatic Pediatric Cases
Details   Retrospective 30 hospitalized pediatric COVID-19 patients and 82 healthy controls, showing significantly lower vitamin D levels in COVID-19 patients.
Levels Patchen et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000255 (Peer Reviewed) severe case, ↓2.0%, p=0.11 Genetically predicted serum vitamin D and COVID-19: a Mendelian randomization study
Details   UK Biobank Mendelian randomization study not finding significant differences in COVID-19 risk. The number of people predicted to have vitamin D deficiency does not appear to be provided. For some background on Mendelian randomization stu..
Levels Nadiger et al., Critical Care Medicine, doi:10.1097/01.ccm.0000726440.30551.47 (Peer Reviewed) Vitamin D Levels in Children With COVID-19 Admitted to the PICU
Details   Retrospective 14 pediatric COVID-19 ICU patients showing that the majority were vitamin D deficient.
Levels Demir et al., Journal of Medical Virology, doi:10.1002/jmv.26832 (Peer Reviewed) severe case, ↓89.3%, p<0.001 Vitamin D deficiency is associated with COVID‐19 positivity and the severity of the disease
Details   Retrospective cohort study of 487 patients finding that lower vitamin D levels is associated with more severe cases as measured by affected lung segments and increased hospitalization time for COVID-19 positive patients, and that lower vi..
PrEP Ma et al., The American Journal of Clinical Nutrition, doi:10.1093/ajcn/nqaa381 (Peer Reviewed) cases, ↓30.0%, p=0.03 Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (COVID-19) infection: a prospective study in UK Biobank
Details   Retrospective 8,297 adults from the UK Biobank showing the habitual use of vitamin D supplements significantly associated with lower risk of COVID-19 cases. Note that the information on vitamin D supplement use was collected a median of 1..
Levels Rafailia et al., medRxiv, doi:10.1101/2021.01.28.21250673 (Preprint) Is vitamin D deficiency associated with the COVID-19 epidemic in Europe
Details   Analysis of vitamin D deficiency and COVID-19 cases and mortality in European countries showing significant correlations with infections (r=0.82, p<0.001) and mortality (r=0.53, p=0.05).
Review Brenner, H., Nutrients, doi:10.3390/nu13020411 (Review) (Peer Reviewed) review Vitamin D Supplementation to Prevent COVID-19 Infections and Deaths—Accumulating Evidence from Epidemiological and Intervention Studies Calls for Immediate Action
Details   Summary of epidemiological and intervention studies for vitamin D supplementation. Author concludes that despite limitations, evidence strongly supports widespread supplementation, in particular for high-risk populations, as well as high-..
Levels Barassi et al., Panminerva Med., doi:10.23736/S0031-0808.21.04277-4 (Peer Reviewed) death, ↓64.9%, p=0.44 Vitamin D in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients with non-invasive ventilation support
Details   Retrospective 118 consecutive hospitalized PCR+ patients in Italy showing higher ventilation and mortality with vitamin D deficiency.
Late Nogués et al., The Journal of Clinical Endocrinology & Metabolism, doi:10.1210/clinem/dgab405 (Peer Reviewed) death, ↓79.0%, p=0.001 Calcifediol Treatment and COVID-19-Related Outcomes
Details   Quasi-randomized trial with 930 hospitalized patients, 447 treated with calcifediol, showing significantly lower ICU admission and death with treatment. Note that the randomization in this trial is by ward. Authors report that patients we..
Levels Walrand, S., Nature, doi:10.1038/s41598-021-81419-w (Peer Reviewed) Autumn COVID-19 surge dates in Europe correlated to latitudes, not to temperature-humidity, pointing to vitamin D as contributing factor
Details   Analysis of the increase in COVID-19 cases in European countries, showing no correlation with temperature, but a significant correlation with country latitude. Since UV radiation decreases earlier for higher latitudes, this supports the t..
Levels Orchard et al., Clin Chem Lab Med, doi:10.1515/cclm-2020-1567 (Peer Reviewed) ICU, ↓58.8%, p=0.001 Vitamin-D levels and intensive care unit outcomes of a cohort of critically ill COVID-19 patients
Details   Retrospective 165 hospitalized patients with known vitamin D levels, showing an associated between vitamin D deficiency and ICU admission. There was no statistically significant difference in clinical outcomes for ICU patients. It's uncle..
PrEP Vasheghani et al., Research Square, doi: 10.21203/ (Preprint) death, ↓30.4%, p=0.45 The Association of 25 (OH) Vitamin D Levels and Severity and Outcome of COVID-19: A Cross-sectional Study
Details   Retrospective 508 hospitalized COVID-19 patients in Iran showing lower mortality with vitamin D supplementation, and an association between low vitamin D levels and disease severity, ICU admission, and increased mortality. Details of supp..
Late Giannini et al., Nutrients, doi:10.3390/nu13010219 (Peer Reviewed) death/ICU, ↓36.6%, p=0.13 Effectiveness of In-Hospital Cholecalciferol Use on Clinical Outcomes in Comorbid COVID-19 Patients: A Hypothesis-Generating Study
Details   Retrospective 91 hospitalized patients, 36 treated with high-dose cholecalciferol, showing lower combined death/ICU admission with treatment. Authors also analyze the relationship with comorbidity burden, finding that the positive effect..
Levels Bennouar et al., Journal of the American College of Nutrition, doi:10.1080/07315724.2020.1856013 (Peer Reviewed) death, ↓85.5%, p=0.002 Vitamin D Deficiency and Low Serum Calcium as Predictors of Poor Prognosis in Patients with Severe COVID-19
Details   Prospective study of 120 severe cases of COVID-19 in Algeria finding low vitamin D and low calcium both associated with increased mortality.
Levels Li et al., Aging and Disease, doi:10.14336/AD.2020.1108 (Peer Reviewed) severe case, ↓36.2%, p<0.0001 Metabolic Healthy Obesity, Vitamin D Status, and Risk of COVID-19
Details   UK Biobank retrospective 353,299 patients showing that vitamin D insufficiency and deficiency are associated with increased COVID-19 risk. This study also analyzes metabolic/obesity phenotypes and the combination with vitamin D status.
Levels Angelidi et al., Mayo Clinic Proceedings, doi:10.1016/j.mayocp.2021.01.001 (Peer Reviewed) death, ↓88.0%, p=0.01 Vitamin D Status is Associated With In-hospital Mortality and Mechanical Ventilation: A Cohort of COVID-19 Hospitalized Patients
Details   Retrospective 144 patients in the USA showing significantly lower mortality for vitamin D levels >=30ng/mL.
Levels Pal et al., Frontiers in Medicine, doi:10.3389/fmed.2020.590805 (Peer Reviewed) High Prevalence of Hypocalcemia in Non-severe COVID-19 Patients: A Retrospective Case-Control Study
Details   Retrospective 72 non-severe COVID-19 patients in India, showing very high levels of vitamin D deficiency (70 of 72 patients).
Levels Amin et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2020-000151 (Peer Reviewed) progression, ↑32.3%, p=0.20 No evidence that vitamin D is able to prevent or affect the severity of COVID-19 in individuals with European ancestry: a Mendelian randomisation study of open data
Details   Analysis of vitamin D levels and COVID-19 cases and severity based on genetic predisposition to higher vitamin D levels or lower vitamin D deficiency, finding no significant association. For some background on Mendelian randomization stu..
PrEP Nikniaz et al., medRxiv, doi:10.1101/2021.01.04.21249219 (Preprint) (meta analysis) death, ↓67.5%, p=0.008 The impact of vitamin D supplementation on mortality rate and clinical outcomes of COVID-19 patients: A systematic review and meta-analysis
Details   Meta analysis of 4 supplementation studies, finding that vitamin D supplementation "seems to decrease the mortality rate, the severity of the disease, and serum levels of the inflammatory markers". Mortality odds ratio OR 0.264,..
Levels Karonova et al., Infectology, doi:10.22625/2072-6732-2020-12-3-21-27 (Peer Reviewed) death, ↓79.4%, p=0.07 Serum 25(oH)D level in patients with CoVID-19
Details   Retrospective 80 COVID-19 patients showing low vitamin D levels associated with severity and mortality.
Levels Szeto et al., Endocrine Research, doi:10.1080/07435800.2020.1867162 (Peer Reviewed) death, ↑5.6%, p=1.00 Vitamin D Status and COVID-19 Clinical Outcomes in Hospitalized Patients
Details   Retrospective 93 hospitalized patients with vitamin D levels 1-365 days before admission, not showing significant differences with vitamin D deficiency or vitamin D levels. Vitamin D levels may vary significantly throughout the year creat..
Review McCullough et al., Reviews in Cardiovascular Medicine, doi:10.31083/j.rcm.2020.04.264 (Review) (Peer Reviewed) review Multifaceted highly targeted sequential multidrug treatment of early ambulatory high-risk SARS-CoV-2 infection (COVID-19)
Details   Review urging early treatment of COVID-19 with sequential multidrug treatment that has been shown to be safe and effective. Proposed treatment includes zinc, vitamin D & C, quercetin, and depending on age, comorbidities, and symptoms may ..
Late Jevalikar et al., Scientific Reports, doi:10.1038/s41598-021-85809-y (preprint 12/28) (Peer Reviewed) death, ↓82.0%, p=0.12 Lack of association of baseline 25-hydroxyvitamin D levels with disease severity and mortality in Indian patients hospitalized for COVID-19
Details   Prospective study of 410 hospitalized patients in India showing lower mortality and ICU admission with cholecalciferol treatment, although not statistically significant with the small number of cases. The median total dose was 60000IU. N..
Late Sistanizad et al., European Journal of Integrative Medicine, doi:10.1016/j.eujim.2020.101271 (Peer Reviewed) death, ↓63.5%, p=0.004 High dose vitamin D improves total serum antioxidant capacity and ICU outcome in critically ill patients - a randomized, double-blind clinical trial
Details   RCT of 30 ventilated ICU patients showing lower mortality with vitamin D treatment, RR 0.36, p = 0.004. Authors do not indicate why the patients were hospitalized or if any of the patients were COVID-19 patients. 300,000 IU intramuscular ..
PrEP Cangiano et al., Aging, doi:10.18632/aging.202307 (Peer Reviewed) death, ↓70.0%, p=0.04 Mortality in an Italian nursing home during COVID-19 pandemic: correlation with gender, age, ADL, vitamin D supplementation, and limitations of the diagnostic tests
Details   70% lower mortality with vitamin D supplementation. Analysis of 98 PCR+ nursing home residents in Italy, mean age 90, vitamin D supplementation RR 0.30, p = 0.04. The paper provides the p value for regression but not the effect size. Trea..
Levels Abdollahi et al., Journal of Medical Virology, doi:10.1002/jmv.26726 (Peer Reviewed) cases, ↓53.9%, p=0.001 The Association Between the Level of Serum 25(OH) Vitamin D, Obesity, and underlying Diseases with the risk of Developing COVID‐19 Infection: A case‐control study of hospitalized patients in Tehran, Iran
Details   Case control study with 201 patients and 201 matched controls in Iran showing vitamin D deficiency associated with COVID-19.
Late Ling et el., Nutrients, doi:10.3390/nu12123799 (Peer Reviewed) death, ↓79.8%, p<0.001 High-Dose Cholecalciferol Booster Therapy is Associated with a Reduced Risk of Mortality in Patients with COVID-19: A Cross-Sectional Multi-Centre Observational Study
Details   80% lower mortality with cholecalciferol booster therapy. Retrospective 986 hospitalized patients in the UK finding that cholecalciferol booster therapy, regardless of baseline serum levels, was associated with a reduced risk of mortality..
News VitaminDForAll (News) news Over 100 Scientists, Doctors, & Leading Authorities Call For Increased Vitamin D Use To Combat COVID-19
Details   Over 100 scientists and doctors call for efforts to increase vitamin D levels. Recommendations include reaching 75 nmol/L serum levels, 2000-4000IU daily supplementation (in the absence of testing), and measurement and treatment in hospit..
Levels Vassiliou et al., Hellenic Journal of Cardiology, doi:10.1016/j.hjc.2020.11.011 (Peer Reviewed) Vitamin D deficiency correlates with a reduced number of natural killer cells in intensive care unit (ICU) and non-ICU patients with COVID-19 pneumonia
Details   Observational study of 29 ICU patients and 10 non-ICU patients showing vitamin D levels positively correlated with cytotoxic T cells, natural killer (NK) cells, NK-T cells, and regulatory T cells.
Levels Vassiliou et al., Nutrients, doi:10.3390/nu12123773 (Peer Reviewed) death, ↓90.9%, p=0.04 Low 25-Hydroxyvitamin D Levels on Admission to the Intensive Care Unit May Predispose COVID-19 Pneumonia Patients to a Higher 28-Day Mortality Risk: A Pilot Study on a Greek ICU Cohort
Details   Small prospective study of 30 ICU patients, showing higher mortality risk for low vitamin D levels. When divided into two groups at the median level, there was 5 of 15 deaths for the low vitamin D group compared to 0 of 15 in the high vit..
Levels Alguwaihes et al., Cardiovascular Diabetology, doi:10.1186/s12933-020-01184-4 (Peer Reviewed) death, ↓85.7%, p=0.007 Diabetes and Covid-19 among hospitalized patients in Saudi Arabia: a single-centre retrospective study
Details   Retrospective 439 diabetic hospitalized patients in Saudi Arabia showing lower mortality with vitamin D >12.5 nmol/L, adjusted hazard ratio aHR 0.14, p = 0.007.
Levels Katz el al., Nutrition, doi:10.1016/j.nut.2020.111106 (Peer Reviewed) cases, ↓78.4%, p<0.001 Increased risk for Covid-19 in patients with Vitamin D deficiency
Details   Retrospective database analysis showing patients with vitamin D deficiency were 4.6 times more likely to be COVID-19 positive, p<0.001.
PrEP Louca et al., medRxiv, doi:10.1101/2020.11.27.20239087 (Preprint) cases, ↓8.0%, p=0.0007 Dietary supplements during the COVID-19 pandemic: insights from 1.4M users of the COVID Symptom Study app - a longitudinal app-based community survey
Details   Survey analysis of dietary supplements showing vitamin D usage associated with lower incidence of COVID-19. These results are for PCR+ cases only, they do not reflect potential benefits of vitamin D for reducing the severity of cases. A..
Levels De Smet et al., American Journal of Clinical Pathology, doi:10.1093/ajcp/aqaa252 (Peer Reviewed) death, ↓70.1%, p=0.02 Serum 25(OH)D Level on Hospital Admission Associated With COVID-19 Stage and Mortality
Details   Retrospective 186 hospitalized patients in Belgium showing that 59% of patients were vitamin D deficient, and that non-vitamin D deficient patients had significantly lower mortality risk, RR 0.26, p = 0.015.
Levels Jain et al., Nature, doi:10.1038/s41598-020-77093-z (Peer Reviewed) ICU, ↓95.4%, p<0.0001 Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers
Details   Prospective study of 91 asymptomatic and 63 ICU patients showing significantly higher vitamin D deficiency in the ICU patients (97% vs. 33%).
Late Murai et al., JAMA, doi:10.1001/jama.2020.26848 (preprint 11/17) (Peer Reviewed) death, ↑48.7%, p=0.43 Effect of a Single High Dose of Vitamin D3 on Hospital Length of Stay in Patients With Moderate to Severe COVID-19: A Randomized Clinical Trial
Details   Very late stage (mean 10 days from symptom onset, 90% on oxygen at baseline) vitamin D supplementation RCT not showing significant differences. Ethnicity was poorly matched between arms, and diabetes was 41% in the treatment arm vs. 29% ..
Levels Luo et al., The Journal of Nutrition, doi:10.1093/jn/nxaa332 (Peer Reviewed) progression, ↓63.0%, p=0.01 Vitamin D Deficiency Is Inversely Associated with COVID-19 Incidence and Disease Severity in Chinese People
Details   Retrospective 335 patients in China compared to 560 matched controls showing significanlty lower risk of severe COVID-19 with vitamin D sufficiency (>=30 nmol/L) OR 0.37, p = 0.014.
Meta Jungreis et al., medRxiv, doi:10.1101/2020.11.08.20222638 (Preprint) Mathematical analysis of Córdoba calcifediol trial suggests strong role for Vitamin D in reducing ICU admissions of hospitalized COVID-19 patients
Details   Analysis of Castillo et al. confirming efficacy of calcifediol treatment. Authors find that issues related to imperfect blinding and comorbidities can not explain the result found. See [1] for a response to issues raised on this analysis.
Late Rastogi et al., Postgraduate Medical Journal, doi:10.1136/postgradmedj-2020-139065 (Peer Reviewed) viral+, ↓52.6%, p=0.02 Short term, high-dose vitamin D supplementation for COVID-19 disease: a randomised, placebo-controlled, study (SHADE study)
Details   53% reduction in PCR+ with high-dose cholecalciferol supplementation. RCT with 16 treatment patients and 24 control patients. Relative risk of PCR+ at 2 weeks with treatment, RR 0.47, p=0.18 25(OH)D levels at day 14 were 52 ng/ml vs. 15..
PrEP Cereda et al., Nutrition, doi:10.1016/j.nut.2020.111055 (Peer Reviewed) death, ↑73.0%, p=0.14 Vitamin D supplementation and outcomes in coronavirus disease 2019 (COVID-19) patients from the outbreak area of Lombardy, Italy
Details   Retrospective 105 Parkinson's disease patients, 92 caregivers, and 127 hospital inpatients, showing higher, but not statistically significant mortality and hospitalization with treatment. Supplementation was defined as >=25,000IU/month fo..
Levels Walk et al., medRxiv, doi:10.1101/2020.11.07.20227512 (Preprint) int./death, ↑0.4%, p=1.00 Vitamin D - contrary to vitamin K - does not associate with clinical outcome in hospitalized COVID-19 patients
Details   Small retrospective study of 135 patients not finding a significant difference in vitamin D status. Patients with good outcomes had a median of 45.0 nmol/L versus 37.7 nmol/L for bad outcomes, p = 0.85. Authors found that vitamin D suffi..
PrEP Annweiler et al., Nutrients, doi:10.3390/nu12113377 (Peer Reviewed) death, ↓93.0%, p=0.02 Vitamin D Supplementation Associated to Better Survival in Hospitalized Frail Elderly COVID-19 Patients: The GERIA-COVID Quasi-Experimental Study
Details   Retrospective study finding that regular bolus vitamin D supplementation was associated with less severe COVID-19 and better survival in frail elderly. For those receiving regular supplementation: Adjusted mortality hazard ratio with su..
Levels Cereda et al., Clinical Nutrition (Edinburgh, Scotland), doi:10.1016/j.clnu.2020.10.055 (Peer Reviewed) death, ↑120.0%, p=0.04 Vitamin D 25OH deficiency in COVID-19 patients admitted to a tertiary referral hospital
Details   Prospective cohort study of 129 adult hospitalized COVID-19 patients finding patients with vitamin D levels >20ng/mL had increased mortality after adjustment. This study does not account for the risk of having a serious enough case to be ..
Late Ohaegbulam et al., American Journal of Therapeutics, doi:10.1097/MJT.0000000000001222 (Peer Reviewed) Vitamin D Supplementation in COVID-19 Patients: A Clinical Case Series
Details   Small case study of 4 vitamin D deficient patients with 2 patients treated with cholecalciferol 1000 IU daily and two patients treated with ergocalciferol 50,000 IU daily for 5 days (high dose), showing that patients receiving high dose t..
Review Mercola et al., Nutrients 2020, 12:11, 3361, doi:10.3390/nu12113361 (Review) (Peer Reviewed) review Evidence Regarding Vitamin D and Risk of COVID-19 and Its Severity
Details   Review of vitamin D and COVID-19 concluding that the evidence seems strong enough that people and physicians can use or recommend vitamin D supplements to prevent or treat COVID-19 in light of their safety and wide therapeutic window.
Levels Abrishami et al., European Journal of Nutrition, doi:10.1007/s00394-020-02411-0 (Peer Reviewed) death, ↓75.9%, p=0.04 Possible association of vitamin D status with lung involvement and outcome in patients with COVID-19: a retrospective study
Details   Retrospective 73 hospitalized patients showing the probability of death in patients with vitamin D deficiency (< 25ng/mL) was 34.6% compared with 6.4% in patients with sufficient vitamin D levels.
Levels Hernández et al., The Journal of Clinical Endocrinology & Metabolism, doi:10.1210/clinem/dgaa733 (Peer Reviewed) death/ICU, ↓83.0%, p<0.0001 Vitamin D Status in Hospitalized Patients with SARS-CoV-2 Infection
Details   Retrospective 216 COVID-19 patients and 197 population controls, showing vitamin D deficiency in 82.2% of COVID-19 cases and 47.2% of population-based controls (P < .0001). Authors note: "We did not find any relationship between vit..
N/A Basha et al., Clinical Epidemiology and Global Health, doi:10.1016/j.cegh.2020.10.005 (Review) (Peer Reviewed) review Is the shielding effect of cholecalciferol in SARS CoV-2 infection dependable? An evidence based unraveling
Details   Review of vitamin D for COVID-19, concluding that the available evidence is very suggestive of protective and preventive effect of vitamin D. Authors note that strict lockdown (longer time indoors and home quarantine) may increase the r..
Levels Macaya et al., Nutr. Hosp., doi:10.20960/nh.03193 (Peer Reviewed) severe case, ↓55.0%, p=0.07 Interaction between age and vitamin D deficiency in severe COVID-19 infection
Details   Retrospective 80 hospitalized patients in Spain showing higher risk of severe COVID-19 with vitamin D deficiency.
PrEP Blanch-Rubió et al., Aging, doi:10.18632/aging.104117 (Peer Reviewed) cases, ↓8.0%, p=0.68 Influence of anti-osteoporosis treatments on the incidence of COVID-19 in patients with non-inflammatory rheumatic conditions
Details   Retrospective 2,102 rheumatology patients in Spain showing lower, but not statistically significant, cases with vitamin D supplementation. Details of vitamin D supplementation are not providied - other patients may have also independently..
Early, PrEP Annweiler et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2020.105771 (Peer Reviewed) death, ↓89.0%, p=0.002 Vitamin D and survival in COVID-19 patients: A quasi-experimental study
Details   Vitamin D3 supplementation during or just before COVID-19 was associated with 68% lower mortality and less severe COVID-19 in frail elderly. Retrospective 66 French nursing home residents, mean age 87.7, 9 control patients, and 57 that r..
Levels Ye et al., Journal of the American College of Nutrition, doi:10.1080/07315724.2020.182600 (Peer Reviewed) hosp., ↓93.4%, p=0.03 Does Serum Vitamin D Level Affect COVID-19 Infection and Its Severity? A Case-Control Study
Details   Case control study in China comparing 62 patients with 80 healthy controls showing vitamin D deficiency is a risk factor for COVID-19, especially for severe/critical cases.
Levels Faniyi et al., medRxiv, doi:10.1101/2020.10.05.20206706 (Preprint) seropositive, ↓28.8%, p=0.003 Vitamin D status and seroconversion for COVID-19 in UK healthcare workers who isolated for COVID-19 like symptoms during the 2020 pandemic
Details   Analysis of vitamin D status and anti-SARS-Cov-2 antibodies in UK healthcare workers finding that Vitamin D deficiency is a risk factor for COVID-19 seroconversion.
Levels Yılmaz et al., Pediatric Pulmonology, doi:10.1002/ppul.25106 (Peer Reviewed) severe case, ↓73.4%, p=1.00 Is vitamin D deficiency a risk factor for COVID‐19 in children?
Details   Retrospective 40 hospitalized pediatric COVID-19 patients and 45 healthy controls showing significantly lower vitamin D levels for COVID-19 patients (13.1 vs. 34.8µg/L), and that, within the hospitalized patients, there was more moderate ..
Levels Karahan et al., J. Nutr. Health Aging, doi:10.1007/s12603-020-1479-0 (Peer Reviewed) death, ↓82.5%, p<0.0001 Impact of Serum 25(OH) Vitamin D Level on Mortality in Patients with COVID-19 in Turkey
Details   Retrospective 149 COVID-19 patients, 69.1% with vitamin D deficiency, showing lower vitamin D levels associated with higher mortality.
Levels Kerget el al., Tuberk Toraks, doi:10.5578/tt.70027 (Peer Reviewed) Evaluation of the relationship of serum vitamin D levels in COVID-19 patients with clinical course and prognosis
Details   Prospective study of 88 hospitalized PCR+ COVID-19 patients and 20 asymptomatic PCR- medical personnel, showing lower vitamin D levels correlated with COVID-19 and with the development of ARDS and MAS.
Levels Maghbooli et al., PLOS One, doi:10.1371/journal.pone.0239799 (Peer Reviewed) death, ↓51.7%, p=0.08 Vitamin D sufficiency, a serum 25-hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection
Details   Retrospective 235 hospitalized patients showing a significant association between vitamin D sufficiency and reduction in clinical severity. For patients over 40, mortality was 9.7% with 25(OH)D levels >30ng/mL, versus 20% for <30ng/mL. ..
Levels Kaufman et al., PLOS One, doi:10.1371/journal.pone.0239252 (Peer Reviewed) cases, ↓53.0%, p<0.001 SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels
Details   Analysis of 191,779 patients in the US finding COVID-19 positivity strongly and inversely associated with circulating 25(OH)D levels. The relationship persists across latitudes, races/ethnicities, gender, and age ranges. COVID-19 adjuste..
Levels Radujkovic et al., Nutrients 2020, 12:9, 2757, doi:10.3390/nu12092757 (Peer Reviewed) death, ↓93.2%, p=0.001 Vitamin D Deficiency and Outcome of COVID-19 Patients
Details   Observational study 185 patients in Germany shows an association between vitamin D status and severity and mortality. Adjusted hazard ratio of vitamin D sufficiency for combined mechanical ventilation and death was HR 0.16, p < 0.001, and..
Levels Israel et al., medRxiv, doi: (Preprint) cases, ↓21.3%, p<0.001 The link between vitamin D deficiency and Covid-19 in a large population
Details   Large observational population study showing a strong association between vitamin D deficiency and COVID-19.
Levels Meltzer et al., JAMA network open, 3:9, doi:10.1001/jamanetworkopen.2020.19722 (Peer Reviewed) cases, ↓43.5%, p=0.02 Association of Vitamin D Status and Other Clinical Characteristics With COVID-19 Test Results
Details   Retrospective 489 patients showing 44% lower risk for COVID-19 with vitamin D sufficiency, relative risk RR = 0.56, p = 0.02.
Late Castillo et al., Journal of Steroid Biochemistry and Molecular Biology, 203, October 2020, doi:10.1016/j.jsbmb.2020.105751 (Peer Reviewed) death, ↓85.4%, p=0.11 Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study
Details   RCT on calcifediol (25-hydroxyvitamin D) treatment for hospitalized COVID-19 patients showing significantly reduced intensive care unit admissions. All patients received standard care including HCQ+AZ. Significantly lower ICU admission ..
Levels Baktash et al., Postgraduate Medical Journal, doi:10.1136/postgradmedj-2020-138712 (Peer Reviewed) death, ↓28.6%, p=0.50 Vitamin D status and outcomes for hospitalised older patients with COVID-19
Details   Prospective study of 105 hospitalized patients, showing lower vitamin D levels in the COVID-19 positive group (27.0 nmol/L vs 52.0 nmol/L, p=0.0008), and non-statistically significant higher mortality with vitamin D deficiency.
Review Xu et al., Journal of Translational Medicine, doi:10.1186/s12967-020-02488-5 (Review) (Peer Reviewed) review The importance of vitamin d metabolism as a potential prophylactic, immunoregulatory and neuroprotective treatment for COVID-19
Details   Review of vitamin D for the prevention and treatment of COVID-19, focusing on preventing SARS-CoV-2 infection, acting as an immunosuppressant inhibiting cytokine release syndrome, and preventing loss of neural sensation by stimulating exp..
Early Afshar et al., Journal of Contemporary Medical Sciences, 10.22317/jcms.v6i4.822 (Peer Reviewed) Suggested role of Vitamin D supplementation in COVID-19 severity
Details   Brief report noting that there was a dramatic and complete resolution of ICU admissions after adding routine vitamin D supplementation to standard of care.
Levels Hastie et al., Diabetes and Metabolic Syndrome: Clinical Research and Reviews, 14:4, 561–565, doi:10.1016/j.dsx.2020.04.050 (Peer Reviewed) death, ↓17.4%, p=0.31 Vitamin D concentrations and COVID-19 infection in UK Biobank
Details   Database analysis of 341,484 patients in the UK with 656 hospitalized confirmed COVID-19 patients and 203 deaths, not showing a statistically significant difference after adjustment. Since adjustment factors may be correlated with vitamin..
Early Espitia-Hernandez et al., Biomedical Research, 31:5 (Peer Reviewed) viral+, ↓97.2%, p<0.0001 Effects of Ivermectin-azithromycin-cholecalciferol combined therapy on COVID-19 infected patients: A proof of concept study
Details   Small study with 28 patients treated with ivermectin + AZ + cholecalciferol and 7 control patients. All treated patients were PCR- at day 10 while all control patients remained PCR+. The mean duration of symptoms was 3 days in the treatm..
Levels Im et al., Int. J. Infect. Dis., doi:10.1016/j.ijid.2020.08.018 (Peer Reviewed) cases, ↓73.1%, p=0.003 Nutritional status of patients with COVID-19
Details   Nutrient study of 50 hospitalized COVID-19 patients in South Korea showing that 76% of patients were vitamin D deficient. Comparison with 150 matched controls showed a higher probability of cases with vitamin D deficiency.
Levels Carpagnano et al., J. Endocrinol. Invest., 2020, Aug 9, 1-7, doi:10.1007/s40618-020-01370-x (Peer Reviewed) death, ↓70.6%, p=0.05 Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19
Details   Retrospective study 42 patients with acute respiratory failure, 81% with low vitamin D levels. After 10 days, patients with severe vitamin D deficiency had a 50% probability of dying, while those with vitamin D ≥ 10 ng/mL had a 5% mortal..
Levels Merzon et al., The FEBS Journal, (Peer Reviewed) hosp., ↓46.4%, p=0.06 Low plasma 25(OH) vitamin D level is associated with increased risk of COVID‐19 infection: an Israeli population‐based study
Details   Analysis of 7,807 patients finding that low vitamin D levels are correlated with increased risk of cases and hospitalization. Adjusted odds ratio OR for sufficient vitamin D level for cases 0.69, p < 0.001, and for hospitalization 0.51, p..
Levels Lansiaux et al., Spat. Spatiotemporal Epidemiol, doi:10.1016/j.sste.2020.100362 (Peer Reviewed) Covid-19 and vit-d: Disease mortality negatively correlates with sunlight exposure
Details   Analysis of COVID-19 mortality rate and sunlight exposure finding a correlation that suggests a protective effect of sunlight exposure. In continental metropolitan France, average annual sunlight hours were found to be significantly cor..
Late Krishnan et al., J Clin Anesth., doi:10.1016/j.jclinane.2020.110005 (Peer Reviewed) death, ↓19.0%, p=0.42 Clinical comorbidities, characteristics, and outcomes of mechanically ventilated patients in the State of Michigan with SARS-CoV-2 pneumonia
Details   Retrospective 152 mechanically ventilated patients in the USA showing unadjusted lower mortality with vitamin C, vitamin D, HCQ, and zinc treatment, statistically significant only for vitamin C.
PrEP Jolliffe et al., medRxiv, doi:10.1101/2020.07.14.20152728 (Peer Reviewed) (meta analysis) meta-analysis Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of aggregate data from randomised controlled trials
Details   Meta analysis of 40 RCTs showing that vitamin D supplementation is safe and reduced risk of acute respiratory infections, odds ratio OR 0.89 [0.81-0.98].
Levels Hamza et al., Pakistan Journal of Medical & Health Sciences (Peer Reviewed) Role of Vitamin D in Pathogenesis and Severity of Coronavirus Disease 2019 (COVID-19) Infection
Details   Prospective study of 168 patients in Pakistan reporting an association between vitamin D deficiency and symptomatic cases. Details of the association are not provided.
Levels Faul et al., Irish Medical Journal, 113:5, 84 (Peer Reviewed) ventilation, ↓69.0%, p=0.03 Vitamin D Deficiency and ARDS after SARS-CoV-2 Infection
Details   Analysis of 33 hospitalized COVID-19 patients with respiratory failure requiring FiO2 greater than 0.4. Intubation hazard ratio for vitamin D sufficiency HR 0.31, p = 0.03.
Levels Panagiotou et al., medRxiv, doi:10.1101/2020.06.21.20136903 (Peer Reviewed) ICU, ↓52.0%, p=0.02 Low serum 25-hydroxyvitamin D (25[OH]D) levels in patients hospitalised with COVID-19 are associated with greater disease severity: results of a local audit of practice
Details   Retrospective analysis 134 hospitalized patients. 19% of ICU patients had 25(OH)D levels > 50 nmol/L vs. 39.1% of non-ICU patients, p=0.02
Levels Mendy et al., medRxiv, doi:10.1101/2020.06.25.20137323 (Preprint) death, ↓7.0%, p=0.89 Factors Associated with Hospitalization and Disease Severity in a Racially and Ethnically Diverse Population of COVID-19 Patients
Details   Retrospective 689 patients showing vitamin D deficiency associated with hospitalization and disease severity.
In Vitro Mok et al., bioRxiv, doi:10.1101/2020.06.21.162396 (Preprint) (In Vitro) in vitro Calcitriol, the active form of vitamin D, is a promising candidate for COVID-19 prophylaxis
Details   In Vitro study showing that the active form of Vitamin D, calcitriol, exhibits significant potent activity against SARS-CoV-2.
Levels Raisi-Estabragh et al., J. Public Health, doi:10.1093/pubmed/fdaa095 (Peer Reviewed) Greater risk of severe COVID-19 in Black, Asian and Minority Ethnic populations is not explained by cardiometabolic, socioeconomic or behavioural factors, or by 25(OH)-vitamin D status: study of 1326 cases from the UK Biobank
Details   UK Biobank retrospective not finding a significant association between vitamin D levels and the risk of PCR+ after adjustment. Since adjustment factors may be correlated with vitamin D deficiency, the extent of any causal contribution of ..
Levels Rhodes et al., BMJ Nutr. Prev. Health, doi:10.1136/bmjnph-2020-000110 (Peer Reviewed) COVID-19 mortality increases with northerly latitude after adjustment for age suggesting a link with ultraviolet and vitamin D
Details   Analysis of COVID-19 mortality and latitude as of May 18, 2020, showing that latitude was significantly associated with mortality (p=0.031), with an estimated 4.4% [0.4%-8.5%] increase in mortality for each 1° further north.
Late Tan et al., Nutrition, doi:10.1016/j.nut.2020.111017 (Peer Reviewed) oxygen, ↓80.5%, p=0.04 Cohort study to evaluate the effect of combination Vitamin D, Magnesium and Vitamin B12 (DMB) on progression to severe outcome in older COVID-19 patients
Details   Observational study of 43 patients >= 50 years old, with 17 patients receiving vitamin D, magnesium, and vitamin B12 (DMB); and 26 control patients, showing a significantly lower need for oxygen therapy and ICU admission with treatment. ..
Levels D'avolio et al., Nutrients, 12:5, 1–7, doi:10.3390/nu12051359 (Peer Reviewed) 25-hydroxyvitamin D concentrations are lower in patients with positive PCR for SARS-CoV-2
Details   Retrospective 107 patients in Switzerland showing lower vitamin D levels (11.1 ng/mL) in PCR positive patients compared with negative patients (24.6 ng/mL), p = 0.004.
Levels Marik et al., Med Drug Discov., doi:10.1016/j.medidd.2020.100041 (Preprint) Does vitamin D status impact mortality from SARS-CoV-2 infection?
Details   Analysis of case fatality rates showing that the CFR was significantly greater for Northern states (>40° latitude) compared to Southern States (6.0% vs. 3.5%, p  < 0 .001), although there were some exceptions with individual states.
Levels Lau et al., medRxiv, doi:10.1101/2020.04.24.20075838 (Preprint) ICU, ↓45.0%, p=0.29 Vitamin D Insufficiency is Prevalent in Severe COVID-19
Details   Analysis of 20 hospitalized COVID-19 patients, 13 requiring ICU admission. 84.6% of the ICU patients had low vitamin D levels versus 57.1% of the non-ICU patients.
Review Grant et al., Nutrients, 12:4, 988, doi:10.3390/nu12040988 (Review) (Peer Reviewed) review Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths
Details   Review of the evidence that vitamin D supplementation could reduce COVID-19 risk.
Review McCullough et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2018.12.010 (Review) (Peer Reviewed) review Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience
Details   Report on the long-term use of vitamin D in hospitalized patients with daily dosing from 5,000 to 50,000IU over 7 years. There were no cases of hypercalcemia or any adverse events related to vitamin D supplementation. Authors conclude tha..
N/A Martineau et al., BMJ 2017, 356, doi:10.1136/bmj.i6583 (Peer Reviewed) (meta analysis) cases, ↓7.3%, p=0.003 Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Details   Meta analysis of 25 RCTs showing vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most be..
N/A Bergman et al., PLoS ONE, 2013, 8:6, doi:10.1371/journal.pone.0065835 (Peer Reviewed) (meta analysis) meta-analysis Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Details   Meta analysis of 11 placebo-controlled studies of 5660 patients. Vitamin D showed a protective effect against RTI (OR 0.64 [0.49-0.84]). The protective effect was larger in studies using once-daily dosing compared to bolus doses (OR = 0...
N/A Palacios et al., J Steroid Biochem Mol Biol., 2014, 144PA, 138–145, doi:10.1016/j.jsbmb.2013.11.003 (Review) (Peer Reviewed) review Is vitamin D deficiency a major global public health problem?
Details   Review showing vitamin D deficiency is common worldwide in all age groups.
Related Mitchell et al., Endocr. Pract., 2012, 18:6, 914–923, doi:10.4158/EP12072.OR (Peer Reviewed) (Related) Prevalence and predictors of vitamin D deficiency in healthy adults
Details   Study of 634 healthy volunteers showing 64% had 25(OH)D ≤ 30 ng/mL. Gender, ethnicity, and multivitamin use were significantly associated with 25(OH)D levels.
PrEP Urashima et al., Am. J. Clin. Nutr. 2010, 91:5, 1255-60, doi:10.3945/ajcn.2009.29094 (Peer Reviewed) Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren
Details   RCT for vitamin D supplementation and seasonal influenza A in schoolchildren, showing 10.8% incidence in children in the vitamin D3 group compared with 18.6% in the placebo group, relative risk RR 0.58 [0.34-0.99], p = 0.04. The reductio..
N/A Carlberg et al., The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2018.01.002 (Peer Reviewed) In vivo response of the human epigenome to vitamin D: A Proof-of-principle study
Details   Epigenome-wide chromatin accessibility study before and after vitamin D supplementation (calcitriol), showing significant changes at hundreds of sites within the epigenome of human leukocytes (part of the immune system).
N/A Cannell et al., Epidemiol Infect., 2006, 134:6. 1129-40, doi:10.1017/S0950268806007175 (Review) (Peer Reviewed) review Epidemic influenza and vitamin D
Details   Review article on the mechanisms of action and seasonality of vitamin D levels, concluding that varying vitamin D levels may be the reason for the seasonality of epidemic influenza.
For search methods, inclusion criteria, effect extraction criteria (more serious outcomes have priority), PRISMA answers, and statistical methods see In Vitro, Ex Vivo, Meta, Theory, Safety, Review, and News items are not included in the study count. There is a total of 148 items. Studies with preprints and journal versions are listed under the earlier preprint date.
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