{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T16:34:24Z","timestamp":1790008464582,"version":"4.0.1"},"reference-count":38,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,9,3]],"date-time":"2024-09-03T00:00:00Z","timestamp":1725321600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Biruni University Scientific Research Coordination Unit (BIRATTO)","award":["Biruni-BAP-2022-01-25"],"award-info":[{"award-number":["Biruni-BAP-2022-01-25"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>This study explores the association of vitamin D-binding protein (VDBP) gene polymorphisms, vitamin D levels, and the severity of COVID-19, including the need for intensive care unit (ICU) hospitalization. We analyzed a cohort of 56 consecutive age- and gender-matched adult COVID-19-positive patients and categorized them into three groups: outpatients with mild illness, inpatients with moderate disease, and ICU patients. We measured levels of free, total, and bioavailable 25-hydroxyvitamin D [25(OH)D], VDBP, and albumin. VDBP polymorphisms rs5488 and rs7041 were identified using real-time PCR. A significant proportion of ICU patients were vitamin D-deficient (56.25%) compared to outpatients (10%) and inpatients (5%) (p = 0.0003). ICU patients also had notably lower levels of VDBP (median: 222 mg\/L) and total 25(OH)D (median: 18.8 ng\/mL). Most patients carried heterozygous rs7041 (60.7%) and wild-type rs4588 (58.9%) genotypes. The distribution of rs7041 SNP varied significantly among groups (p = 0.0301), while rs4588 SNP distribution did not (p = 0.424). Heterozygous rs4588 patients had significantly lower VDBP levels (p = 0.029) and reduced bioavailable 25(OH)D compared to those with wild-type rs4588 (p = 0.020). Our findings indicate that VDBP gene polymorphisms, particularly rs7041 and rs4588, are associated with vitamin D status and the severity of COVID-19. The lower VDBP levels and bioavailable vitamin D in ICU patients suggest that these genetic variants may influence disease severity and hospitalization needs. These results highlight the potential role of VDBP polymorphisms in COVID-19 severity, suggesting that genetic screening could be valuable in assessing the risk of severe outcomes and guiding personalized treatment strategies.<\/jats:p>","DOI":"10.3390\/diagnostics14171941","type":"journal-article","created":{"date-parts":[[2024,9,3]],"date-time":"2024-09-03T04:06:41Z","timestamp":1725336401000},"page":"1941","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Investigation of the Relationship between Vitamin D Deficiency and Vitamin D-Binding Protein Polymorphisms in Severe COVID-19 Patients"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4803-9137","authenticated-orcid":false,"given":"Lutfiye","family":"Karc\u0131o\u011flu Batur","sequence":"first","affiliation":[{"name":"Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet","family":"Dokur","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, Medical Faculty, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1738-8940","authenticated-orcid":false,"given":"Suna","family":"Ko\u00e7","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, Medical Faculty, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet","family":"Karabay","sequence":"additional","affiliation":[{"name":"Department of Infectious Disease, Private Medicana Hospitalis Bah\u00e7elievler, Istanbul 34180, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zeyneb Nur","family":"Akcay","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ezgi","family":"Gunger","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nezih","family":"Hekim","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Biruni University, Istanbul 34015, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,3]]},"reference":[{"key":"ref_1","unstructured":"(2024, June 12). 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