COVID-19 studies:  C19 studies: C19:  IvermectinIVM Vitamin DV.D HC QHC Q Vitamin CV.C ZincZn PXPX BHBH FPVFPV FLVFLV PVP-IPI CICI BLBL RDRD
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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 v43 Vitamin D is effective for COVID-19: real-time meta analysis of 70 studies
• Random effects meta-analysis of the 20 vitamin D COVID-19 treatment studies to date shows an estimated reduction of 62% in the effect measured, RR 0.38 [0.27-0.53]. 95% of the studies to date report positive effects (12 of 20 are statis..
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
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
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
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 Low Serum 25-hydroxyvitamin D (Vitamin D) Level Is Associated With Susceptibility to COVID-19, Severity, and Mortality: A Systematic Review and Meta-Analysis
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
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
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.
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
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
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
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
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
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..
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
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
Retrospective 348 hospitalized patients in Italy showing vitamin D deficiency associated with acute hypoxemic respiratory failure.
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
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
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., Research Square, doi:10.21203/ (Preprint) death, ↓60.9%, p=0.27 Impact of Pulse D Therapy on The Inflammatory Markers in Patients With COVID-19
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
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
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
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
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 Patchen et al., medRxiv, doi:10.1101/2021.01.29.21250759 (Preprint) severe case, ↓2.0%, p=0.11 Genetically predicted serum vitamin D and COVID-19: a Mendelian randomization study
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
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
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
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
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
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-..
Late Nogués et al., SSRN, doi:10.2139/ssrn.3771318 (Preprint) death, ↓64.0%, p=0.001 Calcifediol Treatment and COVID-19-Related Outcomes
Cluster RCT with 930 hospitalized patients, 550 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 were allocate..
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
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..
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
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
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
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
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
Retrospective 144 patients in the USA showing significantly lower mortality for vitamin D levels >=30ng/mL.
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
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
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
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
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)
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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)
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..
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
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
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
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
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
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
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
Retrospective 216 COVID-19 patients and 197 population controls. Vitamin D deficiency was found 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 ..
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
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
Retrospective 80 hospitalized patients in Spain showing higher risk of severe COVID-19 with vitamin D deficiency.
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
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
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
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?
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
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
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
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
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
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
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
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
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
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.
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
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
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
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
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
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
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
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..
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
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 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
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
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
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
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
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
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
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
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?
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
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
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
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
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
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?
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
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
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 Cannell et al., Epidemiol Infect., 2006, 134:6. 1129-40, doi:10.1017/S0950268806007175 (Review) (Peer Reviewed) review Epidemic influenza and vitamin D
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 104 items. Studies with preprints and journal versions are listed under the earlier preprint date.
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