Characterization of COVID-19 patients in clinical, epidemiological, and laboratory settings: the role of vitamin D binding protein and vitamin D level in severity

Serum vitamin D and DBP in COVID-19 patients

Abstract

There are contradictory findings on the role of vitamin D-binding protein in COVID-19 development, disease severity, and outcomes. Therefore, we aimed to explore the association between the serum vitamin D level, DBP, and the COVID-19 severity and outcomes. In this cross-sectional study, we observed the suspected and confirmed admitted patients with COVID-19 for the possible outcomes after measurements of vitamin D, vitamin D binding protein (DBP). The study included patients with a mean age of 70.89 years (range: 28–99), mostly aged ≥60 years (84.81%) and male (54.43%). Most were admitted to medical wards (60.76%) or ICU (39.24%). The majority had confirmed COVID-19 (81.01%), while 12.66% were not diagnosed. Hospitalization duration varied: 1–3 days (21.52%), 4–7 (17.72%), 8–14 (37.97%), and >14 days (22.78%). Outcomes: 53.16% died, 34.18% discharged, 12.66% recovered. Disease severity was critical (41.77%), severe (30.38%), moderate (24.05%), and mild (3.80%). All received oxygen: 56.96% via reservoir mask, 36.71% continuous positive airway pressure (CPAP), and 6.33% nasal mask. Common comorbidities: hypertension (67.09%), diabetes (37.97%), ischemic heart disease (IHD) (25.32%), and smoking (21.52%). Symptoms: shortness of breath (77.22%), cough (75.95%), chest pain (60.76%). Fever types: persistent (44.59%) and high (27.03%). Only 25.32% were vaccinated (Pfizer 45%, AstraZeneca 30%, Sinopharm 25%), mostly with two doses (85%). Vitamin D was low (16.88). DBP protein (mean: 5.51, range: 0.15–25.20) showed no significant differences across outcomes or severity (p > 0.05). Our study's results, particularly the exceptionally low mean DBP value in a cohort with high COVID-19 severity and mortality, highlight a crucial area of investigation.