Abstract
Vitamin D has shown antimicrobial effects. This study aimed to explore the antiviral effects of vitamin D3 on saliva samples collected from patients with coronavirus disease-19 (COVID-19) and compare saliva and swab results to aid in policy development. Saliva and swab samples were collected from adult patients with a positive test for COVID-19 at the King Faisal Specialist Hospital and Research Centre, Jeddah. Patients who were immunocompromised and pregnant and aged < 18 years were excluded. Vitamin D3 compound (100, 300, 800, and 1,200 IU) was added to the first saliva sample in the laboratory (n = 20); the rest of the swab specimens were compared with the saliva samples via real-time polymerase chain reaction. Of the 257 patients, 236 (94.8%) had positive saliva sample test results, 7 (2.8%) had errors, and 6 (2.4%) had negative results. Of the 236 positive tests, 235 (99.6%) had a cycle threshold (Ct) indicating strong positive reactions, and only one (Ct = 28.86) was weak. Among the 236 positive results, 235 (99.6%) exhibited robust positive reactions, indicating a substantial positive sample size. Thus, saliva might be a dependable alternative testing tool when obtaining swab samples from patients is inconvenient or challenging.