COVID-19 is a unique viral infectious illness that causes a variety of symptoms and health hazards, particularly to the respiratory system and has been declared a worldwide pandemic. The disease is characterized by a cytokine release in severe conditions. Interleukin-6 (IL-6), a proinflammatory cytokine, mediates an important immunomodulatory process. Also, vitamin D was identified to have a role in the innate immunity of individuals. Our study was designed to find the role of IL-6 and vitamin D in COVID-19 patients, as well as, to see whether there is a link between vitamin D deficiency and cytokine syndrome development. The study included 90 COVID-19 patients and 30 control people from Baghdad, Iraq. The age of the participants was non-significantly (P>0.05) different between COVID-19 and control, so was the body mass index. IL-6 level was significantly (P<0.05) higher in COVID-19 patients compared to control, while vitamin D level was significantly (P<0.05) reduced in COVID-19 patients. Nevertheless, the results have shown no significant correlation between vitamin D and IL-6 in the serum of COVID-19 patients. Furthermore, both IL-6 and vitamin D exhibited an excellent sensitivity in the diagnosis of COVID-19.
