Abstract: RESEARCH ARTICLE European Journal of Medical and Health Sciences www.ejmed.org Vitamin D Levels among Hospitalized and Non-Hospitalized COVID-19 Patients in Dr. M. Djamil General Hospital Padang Harika Putra, Efrida, and Rismawati Yaswir ABSTRACT Coronavirus Disease 2019 (COVID-19) causes immune system dysregulation and an exaggerated systemic inflammatory response. Vitamin D acts as an immunomodulator that enhances the immunity defense. Degression of vitamin D levels affect the severity of COVID-19 infection Our case-control study compared the vitamin D levels between hospitalized and non-hospitalized COVID-19 patients at RSUP dr. M. Djamil, Padang from February to September 2020. Serum vitamin D levels were categorized as deficiency if the level was less than 20 ng/mL based on the Chemiluminescent Microparticle Immunoassay. The hospitalized group consisted of moderate to critical COVID-19 patients, whereas the nonhospitalized group consisted of the asymptomatic and mild COVID-19 patients according to the Indonesian Ministry of Health Guidelines. Data analysis were performed using T-test and Chi-square with a significant pvalue of less than 0.05. The results showed that most subjects were women between 21–60 years. The mean level of vitamin D (ng/mL) in the hospitalized group was lower than in the non-hospitalized group (15.5 ± 7.72 vs. 19.2 ± 14.30; 95% CI -9.509–2.167; p=0.213). Vitamin D deficiency was found more among hospitalized group than the non-hospitalized group, but not statistically significant (71% vs. 64.5%, p=0.566). It indicated the role of vitamin D in preventing immune system hyperactivation causing COVID-19 cytokine storm. This study concluded no difference in vitamin D levels among the study groups. Nevertheless, further research on vitamin D is needed to determine its role and benefits against COVID-19 infection. Keywords: COVID-19, cytokine storm, inflammation, vitamin D deficiency. I. INTRODUCTION Coronavirus Disease 2019 (COVID-19) is a newly discovered infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) [1]. The SARS-CoV-2 virus exhibits the ability to evade the immune defense, so it can avoid the immune system which plays a significant role in viral clearance during the ongoing infection process [2]. This mechanism causes a strong inflammatory response that enhances immune system hyperactivation and cytokine storm. This pathological process results in serious damage to the host, leading to acute respiratory distress syndrome (ARDS) and mortality. Vitamin D, known for its immunomodulatory effect, has been reported to suppress this process, thereby assumed to prevent the severity of COVID-19 infection [1]-[3]. Vitamin D metabolite is an endogenous steroid hormone synthesized through the effects of ultraviolet radiation on the skin. It also can be exogenously derived through daily supplements and dietary sources [4]. Deficiency of vitamin D is one of the global nutritional health problems, affecting 5.9–13% of the worldwide population [5]. Vitamin D provides an essential role in many physiological functions. Several studies emphasized the effect of vitamin D in the modulation of the DOI: http://dx.doi.org/10.24018/ejmed.2021.3.6.1131 Submitted : November 3, 2021 Published : December 10, 2021 ISSN: 2593-8339 DOI: 10.24018/ejmed.2021.3.6.1131 H. Putra* Clinical Pathology Residency Program, Faculty of Medicine, Andalas University, Dr. M. Djamil Hospital, Padang,..