Vitamin D supplementation benefits COVID-19: A systematic review and meta-analysis
et al., Heliyon, doi:10.1016/j.heliyon.2026.e44988, PROSPERO CRD42022367684, May 2026
Vitamin D for COVID-19
8th treatment shown to reduce risk in
October 2020, now with p < 0.00000000001 from 137 studies, recognized in 18 countries.
No treatment is 100% effective. Protocols
combine treatments.
6,600+ studies for
220+ treatments. c19early.org
|
Systematic review and meta-analysis of 20 RCTs (n = 2,756) showing significantly lower mortality and ICU admission with vitamin D treatment for COVID-19.
22 meta-analyses show significant improvements with vitamin D treatment for mortality1-15,
mechanical ventilation1,5,6,11,16-18 ,
ICU admission1,3,5,6,9,11,13,15-21 ,
hospitalization11,
severity2,4,5,10,22 , and
cases7,20,22 .
Currently there are 137 vitamin D treatment for COVID-19 studies, showing 39% lower mortality [32‑45%], 17% lower ventilation [-5‑35%], 45% lower ICU admission [28‑57%], 22% lower hospitalization [13‑30%], and 17% fewer cases [9‑25%].
1.
Shah et al., Does vitamin D supplementation reduce COVID-19 severity? - a systematic review, QJM: An International Journal of Medicine, doi:10.1093/qjmed/hcac040.
2.
Nikniaz et al., The impact of vitamin D supplementation on mortality rate and clinical outcomes of COVID-19 patients: A systematic review and meta-analysis, Pharmaceutical Sciences, doi:10.34172/PS.2021.13.
3.
Hosseini et al., Effects of Vitamin D Supplementation on COVID-19 Related Outcomes: A Systematic Review and Meta-Analysis, Nutrients, doi:10.3390/nu14102134.
4.
D’Ecclesiis et al., Vitamin D and SARS-CoV2 infection, severity and mortality: A systematic review and meta-analysis, PLOS ONE, doi:10.1371/journal.pone.0268396.
5.
Xie et al., Micronutrient perspective on COVID-19: Umbrella review and reanalysis of meta-analyses, Critical Reviews in Food Science and Nutrition, doi:10.1080/10408398.2023.2174948.
6.
Hariyanto et al., Vitamin D supplementation and Covid‐19 outcomes: A systematic review, meta‐analysis and meta‐regression, Reviews in Medical Virology, doi:10.1002/rmv.2269.
7.
Begum et al., The Role of Vitamin D in COVID-19 Survival and Prevention: A Meta-analysis, Sudan Journal of Medical Sciences, doi:10.18502/sjms.v19i1.15776.
8.
Jamilian et al., 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, Public Health Nutrition, doi:10.1017/S1368980024000934.
9.
Sobczak et al., Effect of Vitamin D3 Supplementation on Severe COVID-19: A Meta-Analysis of Randomized Clinical Trials, Nutrients, doi:10.3390/nu16101402.
10.
Petrelli et al., Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies, The Journal of Steroid Biochemistry and Molecular Biology, doi:10.1016/j.jsbmb.2021.105883.
11.
Asla et al., Vitamin D on COVID-19 Patients During the Pandemic, 2022. A Systematic Review and Meta-Analysis, Current Research in Nutrition and Food Science Journal, doi:10.12944/CRNFSJ.11.1.3.
12.
Kow et al., The impact of vitamin D administration on mortality in COVID-19 patients: a systematic review and meta-analysis of randomized controlled trials, Inflammopharmacology, doi:10.1007/s10787-024-01564-2.
13.
Zhang et al., The impact of supplementing vitamin D through different methods on the prognosis of COVID-19 patients: a systematic review and meta-analysis, Frontiers in Nutrition, doi:10.3389/fnut.2024.1441847.
14.
Doustmohammadian et al., Impact of vitamin D supplementation on COVID-19 mortality: A systematic review and meta-analysis, Nutrition Clinique et Métabolisme, doi:10.1016/j.nupar.2025.12.001.
15.
Yang et al., Vitamin D supplementation benefits COVID-19: A systematic review and meta-analysis, Heliyon, doi:10.1016/j.heliyon.2026.e44988.
16.
Meng et al., The role of vitamin D in the prevention and treatment of SARS-CoV-2 infection: A meta-analysis of randomized controlled trials, Clinical Nutrition, doi:10.1016/j.clnu.2023.09.008.
17.
Yang (B) et al., Therapeutic effects of vitamin D supplementation on COVID-19 aggravation: a systematic review and meta-analysis of randomized controlled trials, Frontiers in Pharmacology, doi:10.3389/fphar.2024.1367686.
18.
Szarpak et al., Vitamin D supplementation to treat SARS-CoV-2 positive patients. Evidence from meta-analysis, Cardiology Journal, doi:10.5603/CJ.a2021.0122.
19.
Tentolouris et al., 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, Diabetes/Metabolism Research and Reviews, doi:10.1002/dmrr.3517.
20.
Sartini et al., Preventive Vitamin D Supplementation and Risk for COVID-19 Infection: A Systematic Review and Meta-Analysis, Nutrients, doi:10.3390/nu16050679.
Yang et al., 13 May 2026, China, peer-reviewed, 4 authors, study period November 2022 - December 2025, trial PROSPERO CRD42022367684.
Contact: houning196@163.com.
Abstract:
Research article
Vitamin D supplementation benefits COVID-19: A systematic review and meta-analysis
Shuangshuang Yang a,b,c , Ke Xu a , Shushu Lu d , Ning Hou a,*
- a Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Province, China
- b Maternal and Child Care Centre of Dezhou, Shandong Province, China
- c Graduate Department, Shandong First Medical University (Shandong Academy of Medical Sciences), Shandong Province, China
d Shandong Mental Health Center, Shandong Province, China
A R T I C L E I N F O
Keywords: COVID-19 Vitamin D Immunity Mortality rate ICU admission rate Length of hospital stay
DOI record:
{
"DOI": "10.1016/j.heliyon.2026.e44988",
"ISSN": [
"2405-8440"
],
"URL": "http://dx.doi.org/10.1016/j.heliyon.2026.e44988",
"alternative-id": [
"S2405844026004998"
],
"article-number": "e44988",
"assertion": [
{
"label": "This article is maintained by",
"name": "publisher",
"value": "Elsevier"
},
{
"label": "Article Title",
"name": "articletitle",
"value": "Vitamin D supplementation benefits COVID-19: A systematic review and meta-analysis"
},
{
"label": "Journal Title",
"name": "journaltitle",
"value": "Heliyon"
},
{
"label": "CrossRef DOI link to publisher maintained version",
"name": "articlelink",
"value": "https://doi.org/10.1016/j.heliyon.2026.e44988"
},
{
"label": "Content Type",
"name": "content_type",
"value": "article"
},
{
"label": "Copyright",
"name": "copyright",
"value": "© 2026 The Authors. Published by Elsevier Ltd."
}
],
"author": [
{
"affiliation": [],
"family": "Yang",
"given": "Shuangshuang",
"sequence": "first"
},
{
"affiliation": [],
"family": "Xu",
"given": "Ke",
"sequence": "additional"
},
{
"affiliation": [],
"family": "Lu",
"given": "Shushu",
"sequence": "additional"
},
{
"ORCID": "https://orcid.org/0000-0001-5494-8460",
"affiliation": [],
"authenticated-orcid": false,
"family": "Hou",
"given": "Ning",
"sequence": "additional"
}
],
"container-title": "Heliyon",
"container-title-short": "Heliyon",
"content-domain": {
"crossmark-restriction": true,
"domain": [
"cell.com",
"elsevier.com",
"sciencedirect.com"
]
},
"created": {
"date-parts": [
[
2026,
5,
14
]
],
"date-time": "2026-05-14T13:20:20Z",
"timestamp": 1778764820000
},
"deposited": {
"date-parts": [
[
2026,
5,
14
]
],
"date-time": "2026-05-14T13:20:28Z",
"timestamp": 1778764828000
},
"funder": [
{
"DOI": "10.13039/501100015507",
"doi-asserted-by": "publisher",
"id": [
{
"asserted-by": "publisher",
"id": "10.13039/501100015507",
"id-type": "DOI"
}
],
"name": "Shandong Provincial Hospital"
}
],
"indexed": {
"date-parts": [
[
2026,
5,
14
]
],
"date-time": "2026-05-14T14:10:26Z",
"timestamp": 1778767826653,
"version": "3.51.4"
},
"is-referenced-by-count": 0,
"issue": "10",
"issued": {
"date-parts": [
[
2026,
6
]
]
},
"journal-issue": {
"issue": "10",
"published-print": {
"date-parts": [
[
2026,
6
]
]
}
},
"language": "en",
"license": [
{
"URL": "https://www.elsevier.com/tdm/userlicense/1.0/",
"content-version": "tdm",
"delay-in-days": 0,
"start": {
"date-parts": [
[
2026,
6,
1
]
],
"date-time": "2026-06-01T00:00:00Z",
"timestamp": 1780272000000
}
},
{
"URL": "https://www.elsevier.com/legal/tdmrep-license",
"content-version": "tdm",
"delay-in-days": 0,
"start": {
"date-parts": [
[
2026,
6,
1
]
],
"date-time": "2026-06-01T00:00:00Z",
"timestamp": 1780272000000
}
},
{
"URL": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
"content-version": "vor",
"delay-in-days": 0,
"start": {
"date-parts": [
[
2026,
4,
23
]
],
"date-time": "2026-04-23T00:00:00Z",
"timestamp": 1776902400000
}
}
],
"link": [
{
"URL": "https://api.elsevier.com/content/article/PII:S2405844026004998?httpAccept=text/xml",
"content-type": "text/xml",
"content-version": "vor",
"intended-application": "text-mining"
},
{
"URL": "https://api.elsevier.com/content/article/PII:S2405844026004998?httpAccept=text/plain",
"content-type": "text/plain",
"content-version": "vor",
"intended-application": "text-mining"
}
],
"member": "78",
"original-title": [],
"page": "e44988",
"prefix": "10.1016",
"published": {
"date-parts": [
[
2026,
6
]
]
},
"published-print": {
"date-parts": [
[
2026,
6
]
]
},
"publisher": "Elsevier BV",
"reference": [
{
"DOI": "10.1016/j.ijid.2026.108522",
"article-title": "Prevalence of post-COVID symptoms across variants of concern and follow-up periods: a systematic review and meta-analysis",
"author": "Lugtu",
"doi-asserted-by": "crossref",
"journal-title": "Int. J. Infect. Dis.",
"key": "10.1016/j.heliyon.2026.e44988_bib2",
"volume": "166",
"year": "2026"
},
{
"DOI": "10.1007/s11154-021-09679-5",
"article-title": "Vitamin D, infections and immunity",
"author": "Ismailova",
"doi-asserted-by": "crossref",
"first-page": "265",
"issue": "2",
"journal-title": "Rev. Endocr. Metab. Disord.",
"key": "10.1016/j.heliyon.2026.e44988_bib6",
"volume": "23",
"year": "2022"
},
{
"DOI": "10.4049/jimmunol.164.5.2405",
"article-title": "1 alpha,25-dihydroxyvitamin D3 inhibits differentiation, maturation, activation, and survival of dendritic cells leading to impaired alloreactive T cell activation",
"author": "Penna",
"doi-asserted-by": "crossref",
"first-page": "2405",
"issue": "5",
"journal-title": "J. Immunol.",
"key": "10.1016/j.heliyon.2026.e44988_bib7",
"volume": "164",
"year": "2000"
},
{
"DOI": "10.3390/nu10111656",
"article-title": "Vitamin D: nutrient, hormone, and immunomodulator",
"author": "Sassi",
"doi-asserted-by": "crossref",
"first-page": "1656",
"issue": "11",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib8",
"volume": "10",
"year": "2018"
},
{
"DOI": "10.3390/nu5072502",
"article-title": "Vitamin D and immune function",
"author": "Prietl",
"doi-asserted-by": "crossref",
"first-page": "2502",
"issue": "7",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib9",
"volume": "5",
"year": "2013"
},
{
"DOI": "10.1371/journal.ppat.1008874",
"article-title": "Exploring links between vitamin D deficiency and COVID-19",
"author": "Mohan",
"doi-asserted-by": "crossref",
"issue": "9",
"journal-title": "PLoS Pathog.",
"key": "10.1016/j.heliyon.2026.e44988_bib10",
"volume": "16",
"year": "2020"
},
{
"DOI": "10.3390/nu12113361",
"article-title": "Evidence regarding vitamin D and risk of COVID-19 and its severity",
"author": "Mercola",
"doi-asserted-by": "crossref",
"first-page": "3361",
"issue": "11",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib11",
"volume": "12",
"year": "2020"
},
{
"article-title": "Interpretation of practice guidelines on clinical issues related to vitamin D nutrition in Chinese children",
"author": "Zhang",
"first-page": "5",
"issue": "5",
"journal-title": "Chinese Journal of Pediatrics",
"key": "10.1016/j.heliyon.2026.e44988_bib12",
"volume": "60",
"year": "2022"
},
{
"article-title": "Analysis of serum 25-hydroxyvitamin D levels and related factors in 4,311 cases of physical examination in a tertiary hospital in Hefei",
"author": "Gao",
"first-page": "1304",
"issue": "8",
"journal-title": "Chinese Family Medicine",
"key": "10.1016/j.heliyon.2026.e44988_bib13",
"volume": "21",
"year": "2023"
},
{
"DOI": "10.1530/EJE-20-0665",
"article-title": "Mechanisms in endocrinology: vitamin D and COVID-19",
"author": "Bilezikian",
"doi-asserted-by": "crossref",
"first-page": "R133",
"issue": "5",
"journal-title": "Eur. J. Endocrinol.",
"key": "10.1016/j.heliyon.2026.e44988_bib14",
"volume": "183",
"year": "2020"
},
{
"article-title": "Could vitamin D supplementation play a role against COVID-19?",
"author": "Li",
"journal-title": "Front. Immunol.",
"key": "10.1016/j.heliyon.2026.e44988_bib15",
"volume": "13",
"year": "2022"
},
{
"DOI": "10.1136/bmj.d5928",
"article-title": "The Cochrane Collaboration's tool for assessing risk of bias in randomised trials",
"author": "Higgins",
"doi-asserted-by": "crossref",
"journal-title": "Br. Med. J.",
"key": "10.1016/j.heliyon.2026.e44988_bib16",
"volume": "343",
"year": "2011"
},
{
"author": "Higgins",
"key": "10.1016/j.heliyon.2026.e44988_bib17",
"series-title": "Cochrane Handbook for Systematic Reviews of Interventions",
"year": "2024"
},
{
"article-title": "Statistical formulae for calculating some 95% confidence intervals",
"author": "Hackshaw",
"first-page": "205",
"key": "10.1016/j.heliyon.2026.e44988_bib18",
"series-title": "A Concise Guide to Clinical Trials",
"year": "2009"
},
{
"DOI": "10.1186/s13063-023-07114-5",
"article-title": "Effect of vitamin D supplementation versus placebo on recovery delay among COVID-19 Tunisian patients: a randomized-controlled clinical trial",
"author": "Abroug",
"doi-asserted-by": "crossref",
"first-page": "123",
"issue": "1",
"journal-title": "Trials",
"key": "10.1016/j.heliyon.2026.e44988_bib19",
"volume": "24",
"year": "2023"
},
{
"DOI": "10.1371/journal.pmed.1003999",
"article-title": "High-dose versus standard-dose vitamin D supplementation in older adults with COVID-19 (COVIT-TRIAL): a multicenter, open-label, randomized controlled superiority trial",
"author": "Annweiler",
"doi-asserted-by": "crossref",
"issue": "5",
"journal-title": "PLoS Med.",
"key": "10.1016/j.heliyon.2026.e44988_bib20",
"volume": "19",
"year": "2022"
},
{
"DOI": "10.1038/s41598-022-22045-y",
"article-title": "Effect of vitamin D3 supplementation on cellular immunity and inflammatory markers in COVID-19 patients admitted to the ICU",
"author": "Bychinin",
"doi-asserted-by": "crossref",
"issue": "1",
"journal-title": "Sci. Rep.",
"key": "10.1016/j.heliyon.2026.e44988_bib21",
"volume": "12",
"year": "2022"
},
{
"DOI": "10.1186/s12916-022-02290-8",
"article-title": "A single-oral bolus of 100,000 IU of cholecalciferol at hospital admission did not improve outcomes in COVID-19 disease: the COVID-VIT-D—a randomised multicentre international clinical trial",
"author": "Cannata-Andía",
"doi-asserted-by": "crossref",
"first-page": "83",
"issue": "1",
"journal-title": "BMC Med.",
"key": "10.1016/j.heliyon.2026.e44988_bib22",
"volume": "20",
"year": "2022"
},
{
"DOI": "10.3390/nu14153048",
"article-title": "Positive effects of vitamin D supplementation in patients hospitalized for COVID-19: a randomized, double-blind, placebo-controlled trial",
"author": "De Niet",
"doi-asserted-by": "crossref",
"first-page": "3048",
"issue": "15",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib23",
"volume": "14",
"year": "2022"
},
{
"DOI": "10.1186/s12906-024-04393-6",
"article-title": "Impact of vitamin D supplementation on the clinical outcomes of COVID-19 pneumonia patients: a single-center randomized controlled trial",
"author": "Dilokpattanamongkol",
"doi-asserted-by": "crossref",
"first-page": "97",
"issue": "1",
"journal-title": "BMC Complement. Med. Ther.",
"key": "10.1016/j.heliyon.2026.e44988_bib24",
"volume": "24",
"year": "2024"
},
{
"DOI": "10.3390/nu15051234",
"article-title": "Vitamin D supplementation and clinical outcomes in severe COVID-19 patients-randomized controlled trial",
"author": "Domazet Bugarin",
"doi-asserted-by": "crossref",
"first-page": "1234",
"issue": "5",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib25",
"volume": "15",
"year": "2023"
},
{
"DOI": "10.3389/fimmu.2025.1593200",
"article-title": "Impact of vitamin D supplementation in the prognosis of patients with SARS-CoV2 pneumonia admitted to the intensive care unit - a randomized controlled trial",
"author": "Gonçalves",
"doi-asserted-by": "crossref",
"journal-title": "Front. Immunol.",
"key": "10.1016/j.heliyon.2026.e44988_bib26",
"volume": "16",
"year": "2025"
},
{
"DOI": "10.5812/jcp-138083",
"article-title": "Efficacy of vitamin D as adjuvant therapy for treatment of hospitalized children with COVID-19: a randomized clinical trial",
"author": "Hashemian",
"doi-asserted-by": "crossref",
"issue": "4",
"journal-title": "J. Compr. Pediatr.",
"key": "10.1016/j.heliyon.2026.e44988_bib27",
"volume": "14",
"year": "2023"
},
{
"DOI": "10.3390/biomedicines11051277",
"article-title": "Effect of single high dose vitamin D substitution in hospitalized COVID-19 patients with vitamin D deficiency on length of hospital stay",
"author": "Jaun",
"doi-asserted-by": "crossref",
"first-page": "1277",
"issue": "5",
"journal-title": "Biomedicines",
"key": "10.1016/j.heliyon.2026.e44988_bib28",
"volume": "11",
"year": "2023"
},
{
"DOI": "10.3390/nu14132602",
"article-title": "Effect of cholecalciferol supplementation on the clinical features and inflammatory markers in hospitalized COVID-19 patients: a randomized, open-label, single-center study",
"author": "Karonova",
"doi-asserted-by": "crossref",
"first-page": "2602",
"issue": "13",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib29",
"volume": "14",
"year": "2022"
},
{
"DOI": "10.1371/journal.pone.0267918",
"article-title": "High-dose vitamin D versus placebo to prevent complications in COVID-19 patients: Multicentre randomized controlled clinical trial",
"author": "Mariani",
"doi-asserted-by": "crossref",
"issue": "5",
"journal-title": "PLoS One",
"key": "10.1016/j.heliyon.2026.e44988_bib30",
"volume": "17",
"year": "2022"
},
{
"DOI": "10.1016/j.cdnut.2023.101971",
"article-title": "Vitamin D and zinc supplementation to improve treatment outcomes among COVID-19 patients in India: results from a double-blind randomized placebo-controlled trial",
"author": "Partap",
"doi-asserted-by": "crossref",
"issue": "8",
"journal-title": "Curr. Dev. Nutr.",
"key": "10.1016/j.heliyon.2026.e44988_bib31",
"volume": "7",
"year": "2023"
},
{
"DOI": "10.1136/postgradmedj-2020-139065",
"article-title": "Short term, high-dose vitamin D supplementation for COVID-19 disease: a randomised, placebo-controlled study (SHADE study)",
"author": "Rastogi",
"doi-asserted-by": "crossref",
"first-page": "87",
"issue": "1156",
"journal-title": "Postgrad. Med. J.",
"key": "10.1016/j.heliyon.2026.e44988_bib32",
"volume": "98",
"year": "2022"
},
{
"DOI": "10.3390/nu13072170",
"article-title": "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",
"author": "Sabico",
"doi-asserted-by": "crossref",
"first-page": "2170",
"issue": "7",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib33",
"volume": "13",
"year": "2021"
},
{
"DOI": "10.3390/jcm10112378",
"article-title": "Vitamin D levels in COVID-19 outpatients from Western Mexico: clinical correlation and effect of its supplementation",
"author": "Sánchez-Zuno",
"doi-asserted-by": "crossref",
"first-page": "2378",
"issue": "11",
"journal-title": "J. Clin. Med.",
"key": "10.1016/j.heliyon.2026.e44988_bib34",
"volume": "10",
"year": "2021"
},
{
"DOI": "10.3390/medicina58101358",
"article-title": "Evidence for the efficacy of a high dose of vitamin D on the hyperinflammation state in moderate-to-severe COVID-19 patients: a randomized clinical trial",
"author": "Sarhan",
"doi-asserted-by": "crossref",
"first-page": "1358",
"issue": "10",
"journal-title": "Medicina (Kaunas)",
"key": "10.1016/j.heliyon.2026.e44988_bib35",
"volume": "58",
"year": "2022"
},
{
"DOI": "10.1093/pubmed/fdae007",
"article-title": "Therapeutic high-dose vitamin D for vitamin D-deficient severe COVID-19 disease: randomized, double-blind, placebo-controlled study (SHADE-S)",
"author": "Singh",
"doi-asserted-by": "crossref",
"first-page": "256",
"issue": "2",
"journal-title": "J. Public Health",
"key": "10.1016/j.heliyon.2026.e44988_bib36",
"volume": "46",
"year": "2024"
},
{
"DOI": "10.5812/jkums-140510",
"article-title": "Effect of high-dose vitamin D on mortality and hospital length of stay in ICU patients with COVID-19: a randomized clinical trial",
"author": "Zamanian",
"doi-asserted-by": "crossref",
"issue": "1",
"journal-title": "J. Kerman Univ. Med. Sci.",
"key": "10.1016/j.heliyon.2026.e44988_bib37",
"volume": "28",
"year": "2024"
},
{
"DOI": "10.3389/fped.2022.943529",
"article-title": "Efficacy and safety of vitamin D supplementation in hospitalized COVID-19 pediatric patients: a randomized controlled trial",
"author": "Zurita-Cruz",
"doi-asserted-by": "crossref",
"journal-title": "Front. Pediatr.",
"key": "10.1016/j.heliyon.2026.e44988_bib38",
"volume": "10",
"year": "2022"
},
{
"DOI": "10.1093/advances/nmab012",
"article-title": "Association of vitamin D status with SARS-CoV-2 infection or COVID-19 severity: a systematic review and meta-analysis",
"author": "Kazemi",
"doi-asserted-by": "crossref",
"first-page": "1636",
"issue": "5",
"journal-title": "Adv. Nutr.",
"key": "10.1016/j.heliyon.2026.e44988_bib39",
"volume": "12",
"year": "2021"
},
{
"DOI": "10.3390/nu14102134",
"article-title": "Effects of vitamin D supplementation on COVID-19 related outcomes: a systematic review and meta-analysis",
"author": "Hosseini",
"doi-asserted-by": "crossref",
"first-page": "2134",
"issue": "10",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib40",
"volume": "14",
"year": "2022"
},
{
"DOI": "10.1080/10408398.2020.1841090",
"article-title": "Vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis",
"author": "Pereira",
"doi-asserted-by": "crossref",
"first-page": "1308",
"issue": "5",
"journal-title": "Crit. Rev. Food Sci. Nutr.",
"key": "10.1016/j.heliyon.2026.e44988_bib41",
"volume": "62",
"year": "2022"
},
{
"DOI": "10.1210/clinem/dgab892",
"article-title": "Prognostic and therapeutic role of vitamin D in COVID-19: systematic review and meta-analysis",
"author": "Dissanayake",
"doi-asserted-by": "crossref",
"first-page": "1484",
"issue": "5",
"journal-title": "J. Clin. Endocrinol. Metab.",
"key": "10.1016/j.heliyon.2026.e44988_bib42",
"volume": "107",
"year": "2022"
},
{
"DOI": "10.1016/j.ijid.2020.12.077",
"article-title": "Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis",
"author": "Liu",
"doi-asserted-by": "crossref",
"first-page": "58",
"journal-title": "Int. J. Infect. Dis.",
"key": "10.1016/j.heliyon.2026.e44988_bib43",
"volume": "104",
"year": "2021"
},
{
"DOI": "10.1016/j.jsbmb.2021.105883",
"article-title": "Therapeutic and prognostic role of vitamin D for COVID-19 infection: a systematic review and meta-analysis of 43 observational studies",
"author": "Petrelli",
"doi-asserted-by": "crossref",
"journal-title": "J. Steroid Biochem. Mol. Biol.",
"key": "10.1016/j.heliyon.2026.e44988_bib44",
"volume": "211",
"year": "2021"
},
{
"article-title": "Guidelines for the diagnosis and treatment of primary osteoporosis",
"first-page": "1671",
"issue": "14",
"journal-title": "Chinese General Practice",
"key": "10.1016/j.heliyon.2026.e44988_bib45",
"volume": "26",
"year": "2022"
},
{
"DOI": "10.1007/s40520-020-01678-x",
"article-title": "Vitamin D supplementation: upper limit for safety revisited?",
"author": "Rizzoli",
"doi-asserted-by": "crossref",
"first-page": "19",
"issue": "1",
"journal-title": "Aging Clin. Exp. Res.",
"key": "10.1016/j.heliyon.2026.e44988_bib46",
"volume": "33",
"year": "2021"
},
{
"DOI": "10.1007/s00198-012-1944-7",
"article-title": "Effect of oral cholecalciferol 2,000 versus 5,000 IU on serum vitamin D, PTH, bone and muscle strength in patients with vitamin D deficiency",
"author": "Diamond",
"doi-asserted-by": "crossref",
"first-page": "1101",
"issue": "3",
"journal-title": "Osteoporos. Int.",
"key": "10.1016/j.heliyon.2026.e44988_bib47",
"volume": "24",
"year": "2013"
},
{
"DOI": "10.1111/all.15136",
"article-title": "Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: a systematic review and meta-analysis",
"author": "Vlieg-Boerstra",
"doi-asserted-by": "crossref",
"first-page": "1373",
"issue": "5",
"journal-title": "Allergy",
"key": "10.1016/j.heliyon.2026.e44988_bib49",
"volume": "77",
"year": "2022"
},
{
"DOI": "10.1136/bmjgh-2020-003176",
"article-title": "Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis",
"author": "Abioye",
"doi-asserted-by": "crossref",
"issue": "1",
"journal-title": "BMJ Glob. Health",
"key": "10.1016/j.heliyon.2026.e44988_bib50",
"volume": "6",
"year": "2021"
},
{
"DOI": "10.1002/rmv.1909",
"article-title": "Vitamin D modulation of innate immune responses to respiratory viral infections",
"author": "Zdrenghea",
"doi-asserted-by": "crossref",
"issue": "1",
"journal-title": "Rev. Med. Virol.",
"key": "10.1016/j.heliyon.2026.e44988_bib51",
"volume": "27",
"year": "2017"
},
{
"DOI": "10.3390/nu15112588",
"article-title": "The vitamin D serum levels in pregnant women affected by COVID-19: a systematic review and meta-analysis",
"author": "Szarpak",
"doi-asserted-by": "crossref",
"first-page": "2588",
"issue": "11",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib52",
"volume": "15",
"year": "2023"
},
{
"DOI": "10.3390/nu15041052",
"article-title": "COVID-19 in pregnancy: influence of body weight and nutritional status on maternal and pregnancy outcomes-a review of literature and meta-analysis",
"author": "Attini",
"doi-asserted-by": "crossref",
"first-page": "1052",
"issue": "4",
"journal-title": "Nutrients",
"key": "10.1016/j.heliyon.2026.e44988_bib53",
"volume": "15",
"year": "2023"
}
],
"reference-count": 48,
"references-count": 48,
"relation": {},
"resource": {
"primary": {
"URL": "https://linkinghub.elsevier.com/retrieve/pii/S2405844026004998"
}
},
"score": 1,
"short-title": [],
"source": "Crossref",
"subject": [],
"subtitle": [],
"title": "Vitamin D supplementation benefits COVID-19: A systematic review and meta-analysis",
"type": "journal-article",
"update-policy": "https://doi.org/10.1016/elsevier_cm_policy",
"volume": "12"
}
