{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T23:38:22Z","timestamp":1776814702602,"version":"3.51.2"},"reference-count":82,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T00:00:00Z","timestamp":1749772800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Nutr."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Vitamin D is suggested as a supportive therapy to reduce the severity of COVID-19 due to its immunomodulatory and anti-inflammatory effects. However, its effect on critical outcomes, such as ICU admissions and mortality, shows significant variation across randomized clinical trials and meta-analyses.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objectives<\/jats:title><jats:p>To summarize the influence of vitamin D supplementation on ICU admissions and mortality among COVID-19 patients.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Overall, 21 eligible studies were retrieved using a comprehensive search from Scopus, PubMed, and Web of Science. A citation matrix was developed, revealing a Corrected Covered Area (CCA) of 0.54, indicating moderate overlap. Fixed-effects models were applied to data with low heterogeneity (ICU admissions: Q\u202f=\u202f10.87, <jats:italic>p<\/jats:italic>\u202f=\u202f0.33), while random-effects models were used for mortality outcomes (Q\u202f=\u202f27.23, <jats:italic>p<\/jats:italic>\u202f=\u202f0.006). Pooled odds ratios (OR) with 95% confidence intervals (CI) quantified the overall effects.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Vitamin D supplementation was associated with a significant 38% reduction in ICU admissions (OR\u202f=\u202f0.62; 95% CI: 0.54\u20130.71) and a 33% reduction in mortality risk (OR\u202f=\u202f0.67; 95% CI: 0.56\u20130.79). The benefit was pronounced in vitamin D-deficient populations, although heterogeneity in mortality outcomes highlighted variability across studies.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>While these findings suggest that vitamin D supplementation may help reduce ICU admissions and mortality among COVID-19 patients\u2014particularly in those with vitamin D deficiency\u2014the results should be interpreted with caution. The observed variability and potential confounding factors underscore the need for further large-scale, randomized controlled trials with standardized dosing protocols before definitive clinical recommendations can be made.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fnut.2025.1559471","type":"journal-article","created":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T05:51:07Z","timestamp":1749793867000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Effect of vitamin D supplementation on COVID-19 outcomes: an umbrella review of systematic reviews"],"prefix":"10.3389","volume":"12","author":[{"given":"Pavlo","family":"Petakh","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Iryna","family":"Kamyshna","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Iryna","family":"Halabitska","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Oleksandr","family":"Kamyshnyi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,6,13]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"157","DOI":"10.23750\/abm.v91i1.9397","article-title":"WHO declares COVID-19 a pandemic","volume":"91","author":"Cucinotta","year":"2020","journal-title":"Acta Biomedi"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"200","DOI":"10.1093\/nutrit\/nuaa081","article-title":"Supplementation with vitamin D in the COVID-19 pandemic?","volume":"79","author":"Hadizadeh","year":"2021","journal-title":"Nutr Rev"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1080\/17476348.2022.2057300","article-title":"Understanding the pathophysiology of typical acute respiratory distress syndrome and severe COVID-19","volume":"16","author":"Ball","year":"2022","journal-title":"Expert Rev Respir Med"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1460318","DOI":"10.3389\/fgene.2024.1460318","article-title":"Genomic insight into COVID-19 severity in MAFLD patients: a single-center prospective cohort study","volume":"15","author":"Buchynskyi","year":"2024","journal-title":"Front Genet"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"985","DOI":"10.3390\/v16060985","article-title":"Modulatory roles of AHR, FFAR2, FXR, and TGR5 gene expression in metabolic-associated fatty liver disease and COVID-19 outcomes","volume":"16","author":"Buchynskyi","year":"2024","journal-title":"Viruses"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1016\/j.jpeds.2020.11.016","article-title":"Severe acute respiratory syndrome coronavirus 2 clinical syndromes and predictors of disease severity in hospitalized children and youth","volume":"230","author":"Fernandes","year":"2021","journal-title":"J Pediatr"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"329","DOI":"10.5455\/medarh.2022.76.329-332","article-title":"Effects of metformin, insulin on hematological parameters of COVID-19 patients with type 2 diabetes","volume":"76","author":"Petakh","year":"2022","journal-title":"Med Arch"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"432","DOI":"10.5603\/DK.a2022.0055","article-title":"Association between use of metformin and insulin with hematological parameters in COVID-19 patients with type 2 diabetes: a single center, cross-sectional study","volume":"11","author":"Petakh","year":"2022","journal-title":"Clin Diabetol"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"566","DOI":"10.1186\/s12879-021-06281-7","article-title":"Vitamin D and COVID-19 severity and related mortality: a prospective study in Italy","volume":"21","author":"Campi","year":"2021","journal-title":"BMC Infect Dis"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"904","DOI":"10.3390\/ph16060904","article-title":"Metformin therapy changes gut microbiota alpha-diversity in COVID-19 patients with type 2 diabetes: the role of SARS-CoV-2 variants and antibiotic treatment","volume":"16","author":"Petakh","year":"2023","journal-title":"Pharmaceuticals"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"1069894","DOI":"10.3389\/fimmu.2023.1069894","article-title":"Efficacy of interferon alpha for the treatment of hospitalized patients with COVID-19: a meta-analysis","volume":"14","author":"Buchynskyi","year":"2023","journal-title":"Front Immunol"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"84","DOI":"10.21315\/mjms2023.30.3.7","article-title":"Risk factors associated with the severity of COVID-19","volume":"30","author":"Martono","year":"2023","journal-title":"Malays J Med Sci"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"1142578","DOI":"10.3389\/fcimb.2023.1142578","article-title":"Gut microbiota in patients with COVID-19 and type 2 diabetes: a culture-based method","volume":"13","author":"Petakh","year":"2023","journal-title":"Front Cell Infect Microbiol"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"1031","DOI":"10.1186\/s13063-020-04928-5","article-title":"COvid-19 and high-dose VITamin D supplementation TRIAL in high-risk older patients (COVIT-TRIAL): study protocol for a randomized controlled trial","volume":"21","author":"Annweiler","year":"2020","journal-title":"Trials"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"154753","DOI":"10.1016\/j.metabol.2021.154753","article-title":"The link between COVID-19 and VItamin D (VIVID): a systematic review and meta-analysis","volume":"119","author":"Bassatne","year":"2021","journal-title":"Metab Clin Exp"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"281","DOI":"10.3390\/v16020281","article-title":"Metformin alters mRNA expression of FOXP3, RORC, and TBX21 and modulates gut microbiota in COVID-19 patients with type 2 diabetes","volume":"16","author":"Petakh","year":"2024","journal-title":"Viruses"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"715","DOI":"10.4149\/BLL_2021_114","article-title":"Linkage of blood pressure, obesity and diabetes mellitus with angiotensinogen gene (AGT 704T>C\/rs699) polymorphism in hypertensive patients","volume":"122","author":"Repchuk","year":"2021","journal-title":"Bratislavske Lekarske Listy"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"443","DOI":"10.1007\/s00018-024-05476-w","article-title":"The interplay of gut microbiota, obesity, and depression: insights and interventions","volume":"81","author":"Halabitska","year":"2024","journal-title":"Cell Mol Life Sci"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"151","DOI":"10.1016\/j.arteri.2020.10.001","article-title":"COVID-19 and diabetes: a bidirectional relationship","volume":"33","author":"Lima-Mart\u00ednez","year":"2021","journal-title":"Clin Invest Arterioscl"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"1711","DOI":"10.1016\/S0140-6736(21)00634-6","article-title":"Ethnic differences in SARS-CoV-2 infection and COVID-19-related hospitalisation, intensive care unit admission, and death in 17 million adults in England: an observational cohort study using the OpenSAFELY platform","volume":"397","author":"Mathur","year":"2021","journal-title":"Lancet"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"e214117","DOI":"10.1001\/jamanetworkopen.2021.4117","article-title":"Association of Vitamin D Levels, race\/ethnicity, and clinical characteristics with COVID-19 test results","volume":"4","author":"Meltzer","year":"2021","journal-title":"JAMA Netw Open"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"1857","DOI":"10.2337\/dbi19-0023","article-title":"Aging, male sex, obesity, and metabolic inflammation create the perfect storm for COVID-19","volume":"69","author":"Mauvais-Jarvis","year":"2020","journal-title":"Diabetes"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"108481","DOI":"10.1016\/j.clim.2020.108481","article-title":"Racial disparity in Covid-19 mortality rates - a plausible explanation","volume":"217","author":"Tal","year":"2020","journal-title":"Clin Immunol"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"e0255132","DOI":"10.1371\/journal.pone.0255132","article-title":"Lower serum 25(OH)D levels associated with higher risk of COVID-19 infection in U.S. black women","volume":"16","author":"Cozier","year":"2021","journal-title":"PLoS One"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"976","DOI":"10.3201\/eid2605.190995","article-title":"Nonpharmaceutical measures for pandemic influenza in nonhealthcare settings-social distancing measures","volume":"26","author":"Fong","year":"2020","journal-title":"Emerg Infect Dis"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"119","DOI":"10.1016\/j.jhin.2020.03.036","article-title":"Risk of nosocomial transmission of coronavirus disease 2019: an experience in a general ward setting in Hong Kong","volume":"105","author":"Wong","year":"2020","journal-title":"J Hosp Infect"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"81","DOI":"10.3201\/eid1201.051370","article-title":"Non-pharmaceutical interventions for pandemic influenza, international measures","volume":"12","author":"Bell","year":"2006","journal-title":"Emerg Infect Dis"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"945","DOI":"10.1016\/S0140-6736(20)30547-X","article-title":"Mitigate the effects of home confinement on children during the COVID-19 outbreak","volume":"395","author":"Wang","year":"2020","journal-title":"Lancet"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"686","DOI":"10.5694\/mja11.10301","article-title":"Vitamin D and health in adults in Australia and New Zealand: a position statement","volume":"196","author":"Nowson","year":"2012","journal-title":"Med J Aust"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"549","DOI":"10.25122\/jml-2021-0101","article-title":"25-OH vitamin D blood serum linkage with VDR gene polymorphism (rs2228570) in thyroid pathology patients in the west-Ukrainian population","volume":"14","author":"Kamyshna","year":"2021","journal-title":"J Med Life"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"881","DOI":"10.2310\/JIM.0b013e31821b8755","article-title":"Vitamin D and the immune system","volume":"59","author":"Aranow","year":"2011","journal-title":"J Invest Med"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"1359","DOI":"10.3390\/nu12051359","article-title":"25-Hydroxyvitamin D concentrations are lower in patients with positive PCR for SARS-CoV-2","volume":"12","author":"D'Avolio","year":"2020","journal-title":"Nutrients"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"2601","DOI":"10.1007\/s40618-021-01566-9","article-title":"Retrospective analysis of vitamin D status on \u0131nflammatory markers and course of the disease in patients with COVID-19 infection","volume":"44","author":"\u00dcnsal","year":"2021","journal-title":"J Endocrinol Investig"},{"key":"ref34","doi-asserted-by":"publisher","first-page":"100041","DOI":"10.1016\/j.medidd.2020.100041","article-title":"Does vitamin D status impact mortality from SARS-CoV-2 infection?","volume":"6","author":"Marik","year":"2020","journal-title":"Med Drug Discov"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"2141","DOI":"10.1007\/s40520-020-01677-y","article-title":"Evidence for possible association of vitamin D status with cytokine storm and unregulated inflammation in COVID-19 patients","volume":"32","author":"Daneshkhah","year":"2020","journal-title":"Aging Clin Exp Res"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1016\/j.nut.2018.11.001","article-title":"Vitamin D in the ICU: more sun for critically ill adult patients?","volume":"61","author":"Langlois","year":"2019","journal-title":"Nutrition"},{"key":"ref37","doi-asserted-by":"publisher","first-page":"106504","DOI":"10.1016\/j.intimp.2020.106504","article-title":"The diagnostic and predictive role of NLR, d-NLR and PLR in COVID-19 patients","volume":"84","author":"Yang","year":"2020","journal-title":"Int Immunopharmacol"},{"key":"ref38","doi-asserted-by":"publisher","first-page":"107065","DOI":"10.1016\/j.intimp.2020.107065","article-title":"Novel serological biomarkers for inflammation in predicting disease severity in patients with COVID-19","volume":"89","author":"Xue","year":"2020","journal-title":"Int Immunopharmacol"},{"key":"ref39","first-page":"j4008","article-title":"AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both","author":"Shea","year":"2017"},{"key":"ref40","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1186\/1471-2288-11-15","article-title":"Methodology in conducting a systematic review of systematic reviews of healthcare interventions","volume":"11","author":"Smith","year":"2011","journal-title":"BMC Med Res Methodol"},{"key":"ref41","doi-asserted-by":"publisher","first-page":"1549","DOI":"10.1002\/sim.10008","article-title":"Sensitivity analysis with iterative outlier detection for systematic reviews and meta-analyses","volume":"43","author":"Meng","year":"2024","journal-title":"Stat Med"},{"key":"ref42","doi-asserted-by":"publisher","first-page":"6079","DOI":"10.1097\/MS9.0000000000002445","article-title":"Efficacy of vitamin D supplementation in the treatment of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials","volume":"86","author":"Adil","year":"2024","journal-title":"Ann Med Surg"},{"key":"ref43","doi-asserted-by":"publisher","first-page":"3794","DOI":"10.3390\/nu16223794","article-title":"The effect of vitamin D supplementation post COVID-19 infection and related outcomes: a systematic review and Meta-analysis","volume":"16","author":"Sartini","year":"2024","journal-title":"Nutrients"},{"key":"ref44","doi-asserted-by":"publisher","first-page":"2134","DOI":"10.3390\/nu14102134","article-title":"Effects of vitamin D supplementation on COVID-19 related outcomes: a systematic review and meta-analysis","volume":"14","author":"Hosseini","year":"2022","journal-title":"Nutrients"},{"key":"ref45","doi-asserted-by":"publisher","first-page":"669","DOI":"10.1007\/s12020-023-03331-9","article-title":"Low vitamin D levels predict outcomes of COVID-19 in patients with both severe and non-severe disease at hospitalization","volume":"80","author":"di Filippo","year":"2023","journal-title":"Endocrine"},{"key":"ref46","doi-asserted-by":"publisher","first-page":"577","DOI":"10.1007\/s12020-022-03239-w","article-title":"Hypocalcemia is associated with adverse outcomes in patients hospitalized with COVID-19","volume":"79","author":"Minasi","year":"2023","journal-title":"Endocrine"},{"key":"ref47","doi-asserted-by":"publisher","first-page":"1441847","DOI":"10.3389\/fnut.2024.1441847","article-title":"The impact of supplementing vitamin D through different methods on the prognosis of COVID-19 patients: a systematic review and meta-analysis","volume":"11","author":"Zhang","year":"2024","journal-title":"Front Nutr"},{"key":"ref48","doi-asserted-by":"publisher","first-page":"1402","DOI":"10.3390\/nu16101402","article-title":"Effect of vitamin D3 supplementation on severe COVID-19: a Meta-analysis of randomized clinical trials","volume":"16","author":"Sobczak","year":"2024","journal-title":"Nutrients"},{"key":"ref49","doi-asserted-by":"publisher","first-page":"2198","DOI":"10.1016\/j.clnu.2023.09.008","article-title":"The role of vitamin D in the prevention and treatment of SARS-CoV-2 infection: a meta-analysis of randomized controlled trials","volume":"42","author":"Meng","year":"2023","journal-title":"Clin Nutr"},{"key":"ref50","doi-asserted-by":"publisher","first-page":"1367686","DOI":"10.3389\/fphar.2024.1367686","article-title":"Therapeutic effects of vitamin D supplementation on COVID-19 aggravation: a systematic review and meta-analysis of randomized controlled trials","volume":"15","author":"Yang","year":"2024","journal-title":"Front Pharmacol"},{"key":"ref51","doi-asserted-by":"publisher","first-page":"1023903","DOI":"10.3389\/fimmu.2022.1023903","article-title":"Vitamin D supplementation for the treatment of COVID-19: a systematic review and meta-analysis of randomized controlled trials","volume":"13","author":"K\u00fcmmel","year":"2022","journal-title":"Front Immunol"},{"key":"ref52","doi-asserted-by":"publisher","first-page":"167","DOI":"10.1016\/j.clnesp.2021.12.033","article-title":"Clinical significance of micronutrient supplements in patients with coronavirus disease 2019: a comprehensive systematic review and meta-analysis","volume":"48","author":"Beran","year":"2022","journal-title":"Clin Nutr ESPEN"},{"key":"ref53","doi-asserted-by":"publisher","first-page":"e70013","DOI":"10.1002\/prp2.70013","article-title":"Effect of vitamin D supplementation on clinical outcomes in adult patients with COVID-19: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials","volume":"12","author":"Ghoreshi","year":"2024","journal-title":"Pharmacol Res Perspect"},{"key":"ref54","doi-asserted-by":"publisher","first-page":"27(1)","DOI":"10.1002\/rmv.1909","article-title":"Vitamin D modulation of innate immune responses to respiratory viral infections","volume":"27","author":"Zdrenghea","year":"2017","journal-title":"Rev Med Virol"},{"key":"ref55","doi-asserted-by":"publisher","first-page":"1523","DOI":"10.3389\/fimmu.2020.01523","article-title":"Vitamin D supplementation: a potential approach for coronavirus\/COVID-19 therapeutics?","volume":"11","author":"Arboleda","year":"2020","journal-title":"Front Immunol"},{"key":"ref56","doi-asserted-by":"publisher","first-page":"2227","DOI":"10.1074\/jbc.C109.071225","article-title":"Direct and indirect induction by 1,25-dihydroxyvitamin D3 of the NOD2\/CARD15-defensin beta2 innate immune pathway defective in Crohn disease","volume":"285","author":"Wang","year":"2010","journal-title":"J Biol Chem"},{"key":"ref57","doi-asserted-by":"publisher","first-page":"564","DOI":"10.1681\/ASN.2013040355","article-title":"Suppression of iron-regulatory hepcidin by vitamin D","volume":"25","author":"Bacchetta","year":"2014","journal-title":"J Am Soc Nephrol"},{"key":"ref58","doi-asserted-by":"publisher","first-page":"G208","DOI":"10.1152\/ajpgi.00398.2007","article-title":"Novel role of the vitamin D receptor in maintaining the integrity of the intestinal mucosal barrier","volume":"294","author":"Kong","year":"2008","journal-title":"Am J Physiol Gastrointest Liver Physiol"},{"key":"ref59","doi-asserted-by":"publisher","first-page":"1186","DOI":"10.3892\/mmr.2015.4685","article-title":"Vitamin D\/VDR signaling attenuates lipopolysaccharide-induced acute lung injury by maintaining the integrity of the pulmonary epithelial barrier","volume":"13","author":"Shi","year":"2016","journal-title":"Mol Med Rep"},{"key":"ref60","doi-asserted-by":"publisher","first-page":"375","DOI":"10.1159\/000455969","article-title":"Vitamin D promotes pneumococcal killing and modulates inflammatory responses in primary human neutrophils","volume":"9","author":"Subramanian","year":"2017","journal-title":"J Innate Immun"},{"key":"ref61","doi-asserted-by":"publisher","first-page":"108841","DOI":"10.1016\/j.jnutbio.2021.108841","article-title":"Vitamin D in autophagy signaling for health and diseases: insights on potential mechanisms and future perspectives","volume":"99","author":"Bhutia","year":"2022","journal-title":"J Nutr Biochem"},{"key":"ref62","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1124\/jpet.107.127209","article-title":"Immune modulatory treatment of trinitrobenzene sulfonic acid colitis with calcitriol is associated with a change of a T helper (Th) 1\/Th17 to a Th2 and regulatory T cell profile","volume":"324","author":"Daniel","year":"2008","journal-title":"J Pharmacol Exp Ther"},{"key":"ref63","doi-asserted-by":"publisher","first-page":"384","DOI":"10.1016\/j.gene.2018.08.017","article-title":"Vitamin D receptor polymorphisms and risk of enveloped virus infection: a meta-analysis","volume":"678","author":"Laplana","year":"2018","journal-title":"Gene"},{"key":"ref64","doi-asserted-by":"publisher","first-page":"112","DOI":"10.1038\/nature03712","article-title":"Angiotensin-converting enzyme 2 protects from severe acute lung failure","volume":"436","author":"Imai","year":"2005","journal-title":"Nature"},{"key":"ref65","doi-asserted-by":"publisher","first-page":"618","DOI":"10.1002\/path.2987","article-title":"Acute respiratory distress syndrome leads to reduced ratio of ACE\/ACE2 activities and is prevented by angiotensin-(1-7) or an angiotensin II receptor antagonist","volume":"225","author":"W\u00f6sten-van Asperen","year":"2011","journal-title":"J Pathol"},{"key":"ref66","doi-asserted-by":"publisher","first-page":"874","DOI":"10.1053\/j.gastro.2013.06.036","article-title":"Activation of the MAS receptor by angiotensin-(1-7) in the renin-angiotensin system mediates mesenteric vasodilatation in cirrhosis","volume":"145","author":"Grace","year":"2013","journal-title":"Gastroenterology"},{"key":"ref67","doi-asserted-by":"publisher","first-page":"7432","DOI":"10.3892\/mmr.2017.7546","article-title":"Vitamin D alleviates lipopolysaccharide-induced acute lung injury via regulation of the renin-angiotensin system","volume":"16","author":"Xu","year":"2017","journal-title":"Mol Med Rep"},{"key":"ref68","doi-asserted-by":"publisher","first-page":"11594","DOI":"10.1080\/07391102.2021.1964601","article-title":"Vitamin D3 and its hydroxyderivatives as promising drugs against COVID-19: a computational study","volume":"40","author":"Song","year":"2022","journal-title":"J Biomol Struct Dyn"},{"key":"ref69","doi-asserted-by":"publisher","first-page":"477","DOI":"10.3390\/v14030477","article-title":"Immunoregulatory intestinal microbiota and COVID-19 in patients with type two diabetes: a double-edged sword","volume":"14","author":"Petakh","year":"2022","journal-title":"Viruses"},{"key":"ref70","doi-asserted-by":"publisher","first-page":"14","DOI":"10.3389\/fimmu.2023.1170012","article-title":"Characterisation of the pro-inflammatory cytokine signature in severe COVID-19","volume":"14","author":"Hawerkamp","year":"2023","journal-title":"Front Immunol"},{"key":"ref71","doi-asserted-by":"publisher","first-page":"597","DOI":"10.1007\/s12020-021-02749-3","article-title":"Vitamin D in the Covid-19 era: a review with recommendations from a G.I.O.S.E.G. expert panel","volume":"72","author":"Ulivieri","year":"2021","journal-title":"Endocrine"},{"key":"ref72","doi-asserted-by":"publisher","first-page":"e127","DOI":"10.1017\/S1368980024000934","article-title":"The role of vitamin D in outcomes of critical care in COVID-19 patients: evidence from an umbrella meta-analysis of interventional and observational studies","volume":"27","author":"Jamilian","year":"2024","journal-title":"Public Health Nutr"},{"key":"ref73","doi-asserted-by":"publisher","first-page":"3470","DOI":"10.3390\/nu15153470","article-title":"The effect of vitamin D supplementation on the length of hospitalisation, intensive care unit admission, and mortality in COVID-19-a systematic review and Meta-analysis","volume":"15","author":"S\u00eerbu","year":"2023","journal-title":"Nutrients"},{"key":"ref74","doi-asserted-by":"publisher","first-page":"1132528","DOI":"10.3389\/fnut.2023.1132528","article-title":"The effects of vitamin D on all-cause mortality in different diseases: an evidence-map and umbrella review of 116 randomized controlled trials","volume":"10","author":"Cao","year":"2023","journal-title":"Front Nutr"},{"key":"ref75","doi-asserted-by":"publisher","first-page":"1131103","DOI":"10.3389\/fnut.2023.1131103","article-title":"Effect of vitamin D supplementation on COVID-19 patients: a systematic review and meta-analysis","volume":"10","author":"Zhang","year":"2023","journal-title":"Front Nutr"},{"key":"ref76","doi-asserted-by":"publisher","first-page":"607","DOI":"10.1007\/s00210-022-02360-x","article-title":"Hospital and laboratory outcomes of patients with COVID-19 who received vitamin D supplementation: a systematic review and meta-analysis of randomized controlled trials","volume":"396","author":"Zaazouee","year":"2023","journal-title":"Naunyn Schmiedeberg's Arch Pharmacol"},{"key":"ref77","doi-asserted-by":"publisher","first-page":"e0268396","DOI":"10.1371\/journal.pone.0268396","article-title":"Vitamin D and SARS-CoV2 infection, severity and mortality: a systematic review and meta-analysis","volume":"17","author":"D'Ecclesiis","year":"2022","journal-title":"PLoS One"},{"key":"ref78","doi-asserted-by":"publisher","first-page":"e3517","DOI":"10.1002\/dmrr.3517","article-title":"The effect of vitamin D supplementation on mortality and intensive care unit admission of COVID-19 patients. A systematic review, meta-analysis and meta-regression","volume":"38","author":"Tentolouris","year":"2022","journal-title":"Diabetes Metab Res Rev"},{"key":"ref79","doi-asserted-by":"publisher","DOI":"10.1002\/14651858.CD015043","article-title":"Vitamin D supplementation for the treatment of COVID-19: a living systematic review","volume":"2021","author":"Stroehlein","year":"2021","journal-title":"Cochrane Database Syst Rev"},{"key":"ref80","doi-asserted-by":"publisher","first-page":"188","DOI":"10.5603\/CJ.a2021.0122","article-title":"Vitamin D supplementation to treat SARS-CoV-2 positive patients Evidence from meta-analysis","volume":"29","author":"Szarpak","year":"2022","journal-title":"Cardiol J"},{"key":"ref81","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1007\/s40618-021-01614-4","article-title":"Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis","volume":"45","author":"Pal","year":"2022","journal-title":"J Endocrinol Investig"},{"key":"ref82","doi-asserted-by":"publisher","first-page":"102189","DOI":"10.1016\/j.dsx.2021.102189","article-title":"Vitamin D supplementation and COVID-19 treatment: a systematic review and meta-analysis","volume":"15","author":"Rawat","year":"2021","journal-title":"Diabete Metab Syndr"}],"container-title":["Frontiers in Nutrition"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnut.2025.1559471\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T05:51:08Z","timestamp":1749793868000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnut.2025.1559471\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,13]]},"references-count":82,"alternative-id":["10.3389\/fnut.2025.1559471"],"URL":"https:\/\/doi.org\/10.3389\/fnut.2025.1559471","relation":{},"ISSN":["2296-861X"],"issn-type":[{"value":"2296-861X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,13]]},"article-number":"1559471"}}