Abstract: Asian Journal of Research in Biochemistry Volume 11, Issue 2, Page 29-38, 2022; Article no.AJRB.94190 ISSN: 2582-0516 Vitamin D, Calcium and Phosphorus Status Involvement during COVID-19 Infection Abdalla Eltoum Ali a,b*, Mohamed Fathy Seyyed Ahmed a, Somia Mohammed Suliman b, Ibrahim Ahamed Ali Karti b and Haidar Eltayeb Saleh c a Department of Clinical Chemistry, Faculty of Medical Laboratory Sciences, University of Alzaeim Alazhari, Sudan. b Program of Medicine & Medical Laboratory Science, Alofoug College of Science & Technology, Khartoum, Sudan. c Clinical Research Laboratory Services, Sylvester Comprehensive Cancer Center (SCCC), Miami University, Miami Fl33136, USA. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/AJRB/2022/v11i2214 Open Peer Review History: This journal follows the Advanced Open Peer Review policy. Identity of the Reviewers, Editor(s) and additional Reviewers, peer review comments, different versions of the manuscript, comments of the editors, etc are available here: https://www.sdiarticle5.com/review-history/94190 Original Research Article Received: 27/09/2022 Accepted: 03/12/2022 Published: 08/12/2022 ABSTRACT Background: COVID-19 is associated with a weak immune system in the human body. Vitamin D plays a role in the body’s immune system and is known to enhance the function of immune cells. In this case, vitamin D inhibits some of the inflammation that can make COVID-19 more severe. The is study aims to determine the serum levels of vitamin D, calcium, and phosphorus in COVID-19 patients. Methods: This was a cross sectional study conducted during the period from January 2021 to July _____________________________________________________________________________________________________ *Corresponding author: E-mail: abdalla.ali2087@yahoo.com; Asian J. Res. Biochem., vol. 11, no. 2, pp. 29-38, 2022 Ali et al.; Asian J. Res. Biochem., vol. 11, no. 2, pp. 29-38, 2022; Article no.AJRB.94190 2021. 50 COVID-19 patients as a case study and 50 healthy individuals as a control group were included in this study. Blood samples were collected from the study group and measured for vitamin D using Enzyme-linked immunosorbent assay (ELISA) technique. Calcium and phosphate were measured by the Cobas 6000 fully automated analyzer (Roche, Germany). Results: The study result showed that in COVID-19 patients, vitamin D (27 ± 5 ng/mL), p-value = 0.000, and calcium (10.2 ± 4 mg/dL), p-value = 0.000, in comparison with control. There was a correlation between vitamin D (r = -.771; p =.000) and calcium (r = -.752; p =.000) and the severity of disease. Conclusions: According to our research, vitamin D deficiency may increase the risk of developing COVID-19 and the risk of developing severe illnesses. Keywords: COVID -19; vitamin D; calcium; phosphate.