{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T06:05:23Z","timestamp":1789884323933,"version":"4.0.1"},"reference-count":39,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2024,11,22]],"date-time":"2024-11-22T00:00:00Z","timestamp":1732233600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Medical University Pleven","award":["8\/2021"],"award-info":[{"award-number":["8\/2021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pediatric Reports"],"abstract":"<jats:p>The aim of our research was to evaluate and analyze serum 25(OH) vitamin D and parathyroid hormone (PTH) levels to investigate whether vitamin D deficiency serves as a risk factor for an increased incidence of acute respiratory infections (ARI) in children. Serum PTH levels were used as an indicator of vitamin D sufficiency, as normal PTH levels require an optimal concentration of 25(OH) vitamin D. The study included 129 children, divided into five subgroups: children with acute bronchopneumonia (n = 42), acute laryngotracheitis (n = 7), acute bronchiolitis (n = 32), acute bronchitis (n = 18), and a control group (n = 30). No statistically significant differences in 25(OH)D levels were observed between the overall population of children with ARI and the control group (p = 0.073). However, significant differences in 25(OH)D levels were identified between the control group and children with bronchopneumonia, acute bronchitis, and laryngotracheitis (p &lt; 0.01, p &lt; 0.05). Regarding PTH levels, statistical significance was found between the control group and the acute bronchiolitis group, due to the high percentage of children with hypervitaminosis in this subgroup. These results highlight the crucial role of vitamin D in the onset and progression of acute respiratory tract infections in children, emphasizing its impact on their overall respiratory health.<\/jats:p>","DOI":"10.3390\/pediatric16040088","type":"journal-article","created":{"date-parts":[[2024,11,22]],"date-time":"2024-11-22T07:54:20Z","timestamp":1732262060000},"page":"1034-1041","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Clinical Study of Vitamin D Levels in Hospitalized Children with Acute Respiratory Infections"],"prefix":"10.3390","volume":"16","author":[{"given":"Gena Stoykova","family":"Petkova","sequence":"first","affiliation":[{"name":"Department of Pediatrics, Medical University Pleven, 5800 Pleven, Bulgaria"},{"name":"Dr. Georgi Stranski University Hospital, 5800 Pleven, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9753-285X","authenticated-orcid":false,"given":"Eleonora Nikolaeva","family":"Mineva","sequence":"additional","affiliation":[{"name":"Department of Social Medicine and Health Management, Faculty of Public Health, Medical University Pleven, 5800 Pleven, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Venetsia Tsvetkova","family":"Botsova","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Medical University Pleven, 5800 Pleven, Bulgaria"},{"name":"Dr. Georgi Stranski University Hospital, 5800 Pleven, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1380","DOI":"10.1016\/S0140-6736(12)61901-1","article-title":"Severe Acute Lower Respiratory Infections Working Group. Global and Regional Burden of Hospital Admissions for Severe Acute Lower Respiratory Infections in Young Children in 2010: A Systematic Analysis","volume":"381","author":"Nair","year":"2013","journal-title":"Lancet"},{"key":"ref_2","unstructured":"GBD 2016 Lower Respiratory Infections Collaborators (2018). Estimates of the Global, Regional, and National Morbidity, Mortality, and Aetiologies of Lower Respiratory Infections in 195 Countries, 1990\u20132016: A Systematic Analysis for the Global Burden of Disease Study 2016. Lancet Infect. Dis., 18, 1191\u20131210."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e12987","DOI":"10.1111\/mcn.12987","article-title":"Association of Vitamin D Supplementation with Respiratory Tract Infection in Infants","volume":"16","author":"Hong","year":"2020","journal-title":"Matern. Child Nutr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1007\/s42000-019-00155-z","article-title":"The Association Between Vitamin D Status and Infectious Diseases of the Respiratory System in Infancy and Childhood","volume":"18","author":"Zisi","year":"2019","journal-title":"Hormones"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Esposito, S., and Lelii, M. (2015). Vitamin D and Respiratory Tract Infections in Childhood. BMC Infect. Dis., 15.","DOI":"10.1186\/s12879-015-1196-1"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1007\/s11154-021-09679-5","article-title":"Vitamin D, Infections and Immunity","volume":"23","author":"Ismailova","year":"2022","journal-title":"Rev. Endocr. Metab. Disord."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2909","DOI":"10.4049\/jimmunol.173.5.2909","article-title":"Cutting Edge: 1,25-Dihydroxyvitamin D3 Is a Direct Inducer of Antimicrobial Peptide Gene Expression","volume":"173","author":"Wang","year":"2004","journal-title":"J. Immunol."},{"key":"ref_8","first-page":"176","article-title":"Review Paper. Vitamin D Impact on Immune Functions: Implications for Preventive Strategy of Allergic Disease?","volume":"29","year":"2012","journal-title":"Adv. Dermatol. Allergol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7090","DOI":"10.4049\/jimmunol.181.10.7090","article-title":"Respiratory Epithelial Cells Convert Inactive Vitamin D to Its Active Form: Potential Effects on Host Defense1","volume":"181","author":"Hansdottir","year":"2008","journal-title":"J. Immunol."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Palacios, C., and Gonzalez, L. (2013). Is Vitamin D Deficiency a Major Global Public Health Problem?. J. Steroid Biochem. Mol. Biol., 144.","DOI":"10.1016\/j.jsbmb.2013.11.003"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Wimalawansa, S.J. (2023). Infections and Autoimmunity\u2014The Immune System and Vitamin D: A Systematic Review. Nutrients, 15.","DOI":"10.3390\/nu15173842"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"33","DOI":"10.14748\/bro.v64i1.6668","article-title":"Vitamin D status in children with myopia","volume":"64","author":"Veleva","year":"2020","journal-title":"Bulg. Rev. Ophthalmol."},{"key":"ref_13","first-page":"98","article-title":"Vitamin D3 Status in Children with Acute Diarrhea","volume":"1","author":"Mileva","year":"2014","journal-title":"Integr. Food Nutr. Metab."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3589","DOI":"10.5272\/jimab.2021271.3589","article-title":"Vitamin D Status and Dietary Habits of Children with Adolescent Idiopathic Scoliosis in Varna","volume":"27","author":"Marinov","year":"2021","journal-title":"JofIMAB"},{"key":"ref_15","first-page":"10","article-title":"Vitamin D Status in Children with Chronic Lung Disease","volume":"62","author":"Velikova","year":"2018","journal-title":"J. Contemp. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"373","DOI":"10.15789\/2220-7619-AAB-1765","article-title":"Association of Low Vitamin D Status with Childhood Pneumonia Severity in Hospitalized Bulgarian Patients","volume":"12","author":"Rimpova","year":"2021","journal-title":"Russ. J. Infect. Immun."},{"key":"ref_17","first-page":"232","article-title":"What is Vitamin D\u2014The vitamin-hormone?","volume":"2","author":"Burgazliev","year":"2010","journal-title":"Sci. Diet."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.annepidem.2007.12.001","article-title":"Vitamin D Status: Measurement, Interpretation and Clinical Application","volume":"19","author":"Holick","year":"2009","journal-title":"Ann. Epidemiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1097\/MED.0b013e328317ca6c","article-title":"Assessment of Vitamin D Status and Definition of a Normal Circulating Range of 25-Hydroxyvitamin D","volume":"15","author":"Hollis","year":"2008","journal-title":"Curr. Opin. Endocrinol. Diabetes Obes."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1212","DOI":"10.1210\/jcem.86.3.7327","article-title":"A Global Study of Vitamin D Status and Parathyroid Function in Postmenopausal Women with Osteoporosis: Baseline Data from the Multiple Outcomes of Raloxifene Evaluation Clinical Trial","volume":"86","author":"Lips","year":"2001","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_21","unstructured":"Borisova, A.-M., Boyanov, M., Kolarov, Z., Popivanov, P., Stoilov, R., Svinarov, D., Shinkov, A., and Pilosof, V. (2019). Recommendation for Diagnosis, Prevention and Treatment of Vitamin D Deficiency, Bulgarian Society of Endocrinology."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"881","DOI":"10.2310\/JIM.0b013e31821b8755","article-title":"Vitamin D and the I mmune System","volume":"59","author":"Aranow","year":"2011","journal-title":"J. Investig. Med."},{"key":"ref_23","first-page":"276","article-title":"Vitamin D and Respiratory Infections in Infants and Toddlers: A Nutri-Shine Perspective","volume":"4","author":"Balan","year":"2013","journal-title":"Handb. Vitam. D Hum. Health"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"94","DOI":"10.32641\/rchped.v90i1.747","article-title":"Vitamin D and pediatrics respiratory diseases","volume":"90","author":"Cepeda","year":"2019","journal-title":"Rev. Chil. Pediatr."},{"key":"ref_25","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_26","doi-asserted-by":"crossref","first-page":"2001","DOI":"10.1007\/s00394-017-1564-2","article-title":"A Systematic Review of Vitamin D Status in Southern European Countries","volume":"57","author":"Manios","year":"2018","journal-title":"Eur. J. Nutr."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1210\/endrev\/bnae009","article-title":"Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows","volume":"45","author":"Giustina","year":"2024","journal-title":"Endocr. Rev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e027666","DOI":"10.1136\/bmjopen-2018-027666","article-title":"Importance of Vitamin D in Acute and Critically Ill Children with Subgroup Analyses of Sepsis and Respiratory Tract Infections: A Systematic Review and Meta-Analysis","volume":"9","author":"Cariolou","year":"2019","journal-title":"BMJ Open"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Corsello, A., Spolidoro, G.C.I., Milani, G.P., and Agostoni, C. (2023). Vitamin D in Pediatric Age: Current Evidence, Recommendations, and Misunderstandings. Front. Med., 10.","DOI":"10.3389\/fmed.2023.1107855"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"P23","DOI":"10.1530\/EJE-18-0736","article-title":"Current Vitamin D Status in European and Middle East Countries and Strategies to Prevent Vitamin D Deficiency: A Position Statement of the European Calcified Tissue Society","volume":"180","author":"Lips","year":"2019","journal-title":"Eur. J. Endocrinol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.1210\/jc.2011-0385","article-title":"Evaluation, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline","volume":"96","author":"Holick","year":"2011","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_32","first-page":"204","article-title":"Vitamin D and Acute Respiratory Infections in Children","volume":"63","author":"Umeadi","year":"2022","journal-title":"Niger. Med. J. J. Niger. Med. Assoc."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Kuang, L., Liang, Z., Wang, C., Lin, T., Zhang, Y., and Zhu, B. (2023). Serum 25-Hydroxy Vitamin D Levels in Children with Acute Respiratory Infections Caused by Respiratory Virus or Atypical Pathogen Infection. Nutrients, 15.","DOI":"10.3390\/nu15061486"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"e9060","DOI":"10.1097\/MD.0000000000009060","article-title":"Association between Serum 25-Hydroxyvitamin D Concentration and Pulmonary Infection in Children","volume":"97","author":"Li","year":"2018","journal-title":"Medicine"},{"key":"ref_35","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_36","doi-asserted-by":"crossref","unstructured":"Levita, J., Wilar, G., Wahyuni, I., Bawono, L.C., Ramadaini, T., Rohani, R., and Diantini, A. (2023). Clinical Toxicology of Vitamin D in Pediatrics: A Review and Case Reports. Toxics, 11.","DOI":"10.3390\/toxics11070642"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.1007\/s00431-024-05513-7","article-title":"Association of Vitamin D with Disease Severity in Infants with Bronchiolitis","volume":"183","author":"Mittal","year":"2024","journal-title":"Eur. J. Pediatr."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Golan-Tripto, I., Loewenthal, N., Tal, A., Dizitzer, Y., Baumfeld, Y., and Goldbart, A. (2021). Vitamin D Deficiency in Children with Acute Bronchiolitis: A Prospective Cross-Sectional Case- Control Study. BMC Pediatr., 21.","DOI":"10.1186\/s12887-021-02666-4"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Alaka\u015f, Y., Celilo\u011flu, C., Tolunay, O., and Matyar, S. (2021). The Relationship between Bronchiolitis Severity and Vitamin D Status. J. Trop. Pediatr., 67.","DOI":"10.1093\/tropej\/fmab081"}],"container-title":["Pediatric Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2036-7503\/16\/4\/88\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:37:10Z","timestamp":1760114230000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2036-7503\/16\/4\/88"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,22]]},"references-count":39,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["pediatric16040088"],"URL":"https:\/\/doi.org\/10.3390\/pediatric16040088","relation":{},"ISSN":["2036-7503"],"issn-type":[{"value":"2036-7503","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,22]]}}}