{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T06:07:40Z","timestamp":1789884460004,"version":"4.0.1"},"reference-count":31,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T00:00:00Z","timestamp":1731974400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cVictor Babes\u201d University of Medicine and Pharmacy"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background and Objectives: Recent studies suggest that vitamin D supplementation and higher serum 25-hydroxyvitamin D (25-OHD) concentrations may reduce the incidence of respiratory infections in children and adolescents. This cross-sectional study aimed to evaluate the association between different concentrations of vitamin D supplementation, serum 25-OHD concentrations, and the frequency of respiratory infections among individuals aged 1 to 18 years, for a duration of 2 years. Methods: Concerning sun exposure in relation to vitamin D, the study took place in Romania, at approximately 45-degree northern latitude. A total of 194 patients were divided into groups based on weekly vitamin D supplementation (&lt;400 IU, 400\u2013800 IU, &gt;800 IU), serum 25-OHD concentrations (&lt;20 ng\/mL, 20\u201330 ng\/mL, &gt;30 ng\/mL), and age (&lt;6 years, 6\u201312 years, 12\u201318 years). The overall incidence of respiratory infections was 41.2%. Results: Participants receiving &gt;800 IU\/week had a significantly lower incidence of infections (16.7%) compared to those receiving &lt;400 IU\/week (60.0%, p &lt; 0.001). Similarly, participants with serum 25-OHD concentrations &gt;30 ng\/mL had an infection rate of 16.7%, compared to 61.4% in those with concentrations &lt;20 ng\/mL (p &lt; 0.001). Age-specific analyses revealed that the protective effect of vitamin D was most pronounced in children under 6 years old. Logistic regression showed that higher vitamin D supplementation and serum 25-OHD concentrations were independently associated with reduced odds of respiratory infections (OR = 0.25 and OR = 0.22, respectively, p &lt; 0.001). Conclusions: These findings support the potential role of vitamin D supplementation in preventing respiratory infections in the pediatric population.<\/jats:p>","DOI":"10.3390\/nu16223953","type":"journal-article","created":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T11:58:07Z","timestamp":1732017487000},"page":"3953","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Assessing the Impact of Vitamin D Supplementation on Respiratory Infections in Children and Adolescents: A Cross-Sectional Study"],"prefix":"10.3390","volume":"16","author":[{"given":"Elena","family":"Tanase","sequence":"first","affiliation":[{"name":"Doctoral School, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Larisa Mihaela","family":"Marusca","sequence":"additional","affiliation":[{"name":"Doctoral School, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"},{"name":"Laboratory Medicine, \u201cLouis Turcanu\u201d Emergency Hospital for Children, 300011 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6133-0204","authenticated-orcid":false,"given":"Florin George","family":"Horhat","sequence":"additional","affiliation":[{"name":"Multidisciplinary Research Center on Antimicrobial Resistance (MULTI-REZ), Microbiology Department, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monica","family":"Susan","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine I, Centre for Preventive Medicine, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3531-3974","authenticated-orcid":false,"given":"Razvan","family":"Susan","sequence":"additional","affiliation":[{"name":"Department of Family Medicine, Centre for Preventive Medicine, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1836-6927","authenticated-orcid":false,"given":"Razvan","family":"Horhat","sequence":"additional","affiliation":[{"name":"Department of Restorative Dentistry, Faculty of Dentistry, Digital and Advanced Technique for Endodontic, Restorative and Prosthetic Treatment Research Center (TADERP), \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4351-7726","authenticated-orcid":false,"given":"Stefania","family":"Dinu","sequence":"additional","affiliation":[{"name":"Department of Pedodontics, Faculty of Dental Medicine, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tiberiu-Liviu","family":"Dragomir","sequence":"additional","affiliation":[{"name":"Department V of Internal Medicine I and Medical Semiology II, \u2018\u2019Victor Babes\u2019\u2019 University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sonia","family":"Tanasescu","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, \u201cVictor Babes\u201d University of Medicine and Pharmacy Timisoara, 300041 Timisoara, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1007\/s11926-008-0020-y","article-title":"Calcium and vitamin D: Skeletal and extraskeletal health","volume":"10","author":"Khazai","year":"2008","journal-title":"Curr. Rheumatol. Rep."},{"key":"ref_2","unstructured":"Del Valle, H.B., Yaktine, A.L., Taylor, C.L., and Ross, A.C. (2024, September 27). Overview of Vitamin D, Dietary Reference Intakes for Calcium and Vitamin D, Available online: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK56061\/."},{"key":"ref_3","first-page":"e46819","article-title":"The Sunlight-Vitamin D Connection: Implications for Patient Outcomes in the Surgical Intensive Care Unit","volume":"15","author":"Nagaria","year":"2023","journal-title":"Cureus"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.amjsurg.2011.07.021","article-title":"Worsening severity of vitamin D deficiency is associated with increased length of stay, surgical intensive care unit cost, and mortality rate in surgical intensive care unit patients","volume":"204","author":"Matthews","year":"2012","journal-title":"Am. J. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2047","DOI":"10.1016\/S0140-6736(22)00478-0","article-title":"Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: A systematic analysis","volume":"399","author":"Li","year":"2022","journal-title":"Lancet"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e497","DOI":"10.1016\/S2214-109X(19)30545-5","article-title":"Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018: A systematic review and modelling study","volume":"8","author":"Wang","year":"2020","journal-title":"Lancet Glob. Health"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.1016\/j.cell.2018.06.045","article-title":"Stereotypic Immune System Development in Newborn Children","volume":"174","author":"Olin","year":"2018","journal-title":"Cell"},{"key":"ref_8","first-page":"e29205","article-title":"Role of Vitamin D Deficiency in Increased Susceptibility to Respiratory Infections Among Children: A Systematic Review","volume":"14","author":"Raju","year":"2022","journal-title":"Cureus"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Marusca, L.M., Reddy, G., Blaj, M., Prathipati, R., Rosca, O., Bratosin, F., Bogdan, I., Horhat, R.M., Tapos, G.-F., and Marti, D.-T. (2023). The Effects of Vitamin D Supplementation on Respiratory Infections in Children under 6 Years Old: A Systematic Review. Diseases, 11.","DOI":"10.3390\/diseases11030104"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e12","DOI":"10.4110\/in.2020.20.e12","article-title":"Vitamin D-Cathelicidin Axis: At the Crossroads Between Protective Immunity and Pathological Inflammation during Infection","volume":"20","author":"Chung","year":"2020","journal-title":"Immune Netw."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.2217\/fmb.09.87","article-title":"The vitamin D-antimicrobial peptide pathway and its role in protection against infection","volume":"4","author":"Gombart","year":"2009","journal-title":"Future Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3310\/hta23020","article-title":"Vitamin D supplementation to prevent acute respiratory infections: Individual participant data meta-analysis","volume":"23","author":"Martineau","year":"2019","journal-title":"Health Technol. Assess."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"949","DOI":"10.21873\/invivo.13525","article-title":"A Case Study of Vitamin D Supplementation Therapy and Acute Respiratory Tract Infection","volume":"38","author":"Simanek","year":"2024","journal-title":"Vivo"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Pludowski, P. (2023). Supplementing Vitamin D in Different Patient Groups to Reduce Deficiency. Nutrients, 15.","DOI":"10.3390\/nu15173725"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"25","DOI":"10.4274\/jcrpe.574","article-title":"Vitamin D deficiency in children and adolescents","volume":"4","year":"2012","journal-title":"J. Clin. Res. Pediatr. Endocrinol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1907","DOI":"10.1210\/clinem\/dgae290","article-title":"Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline","volume":"109","author":"Demay","year":"2024","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3","DOI":"10.4103\/0976-9668.149069","article-title":"Prevalence of acute respiratory infection among under-five children in urban and rural areas of puducherry, India","volume":"6","author":"Kumar","year":"2015","journal-title":"J. Nat. Sci. Biol. Med."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Nicolae, M., Mihai, C.M., Chisnoiu, T., Balasa, A.L., Frecus, C.E., Mihai, L., Lupu, V.V., Ion, I., Pantazi, A.C., and Twakor, A.N. (2023). Immunomodulatory Effects of Vitamin D in Respiratory Tract Infections and COVID-19 in Children. Nutrients, 15.","DOI":"10.3390\/nu15153430"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1111\/j.1365-2249.2009.04001.x","article-title":"Vitamin D and respiratory health","volume":"158","author":"Hughes","year":"2009","journal-title":"Clin. Exp. Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1933","DOI":"10.3390\/nu7031933","article-title":"Vitamin D status and acute respiratory infection: Cross sectional results from the United States National Health and Nutrition Examination Survey, 2001\u20132006","volume":"7","author":"Monlezun","year":"2015","journal-title":"Nutrients"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e014635","DOI":"10.1136\/bmjopen-2016-014635","article-title":"Daycare attendance and respiratory tract infections: A prospective birth cohort study","volume":"7","author":"Toivonen","year":"2017","journal-title":"BMJ Open"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1097\/MOG.0b013e32833d4b9f","article-title":"Vitamin D and mucosal immune function","volume":"26","author":"Sun","year":"2010","journal-title":"Curr. Opin. Gastroenterol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"White, J.H. (2022). Emerging Roles of Vitamin D-Induced Antimicrobial Peptides in Antiviral Innate Immunity. Nutrients, 14.","DOI":"10.3390\/nu14020284"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Dong, Y., Chen, L., Huang, Y., Raed, A., Havens, R., Dong, Y., and Zhu, H. (2022). Sixteen-Week Vitamin D3 Supplementation Increases Peripheral T Cells in Overweight Black Individuals: Post hoc Analysis of a Randomized, Double-Blinded, Placebo-Controlled Trial. Nutrients, 14.","DOI":"10.3390\/nu14193922"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1111\/imm.12610","article-title":"Vitamin D immunoregulation through dendritic cells","volume":"148","author":"Bscheider","year":"2016","journal-title":"Immunology"},{"key":"ref_26","first-page":"e27864","article-title":"A Hospital-Based Study of Vitamin D Levels in Children with Recurrent Respiratory Infections","volume":"14","author":"Jaybhaye","year":"2022","journal-title":"Cureus"},{"key":"ref_27","first-page":"CD008824","article-title":"Vitamin D supplementation for preventing infections in children under five years of age","volume":"11","author":"Yakoob","year":"2016","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1016\/S2213-8587(21)00051-6","article-title":"Vitamin D supplementation to prevent acute respiratory infections: A systematic review and meta-analysis of aggregate data from randomised controlled trials","volume":"9","author":"Sluyter","year":"2021","journal-title":"Lancet Diabetes Endocrinol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1111\/irv.12615","article-title":"Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: A randomized controlled trial","volume":"13","author":"Loeb","year":"2019","journal-title":"Influ. Other Respir. Viruses"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"114249","DOI":"10.1016\/j.jpeds.2024.114249","article-title":"Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial","volume":"275","author":"Reyes","year":"2024","journal-title":"J. Pediatr."},{"key":"ref_31","first-page":"204","article-title":"Vitamin D and Acute Respiratory Infections in Children","volume":"63","author":"Umeadi","year":"2022","journal-title":"Niger. Med. J."}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/16\/22\/3953\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:35:24Z","timestamp":1760114124000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/16\/22\/3953"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,19]]},"references-count":31,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2024,11]]}},"alternative-id":["nu16223953"],"URL":"https:\/\/doi.org\/10.3390\/nu16223953","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,19]]}}}