ABSTRACT
Background: Vitamin D can stall hyper-inflammatory responses, and there are mechanistic reasons for the positive effects of vitamin D in COVID-19 patients. Objectives: Therefore, this study aimed to evaluate the effect of a single high dose of vitamin D on inflammatory markers in critical patients with COVID-19. Design and patients: A single center, double-blind, randomized clinical trial was conducted on 61 patients with COVID-19 admitted to the intensive care units. The intervention and placebo groups received a dose of 300,000 IU vitamin D intramuscularly and identical placebo respectively. Patients were followed up for one week. Lactate Dehydrogenase (LDH) (IU/ml), C-reactive protein (CRP) (mg/L), interleukin-6 (IL-6) (Pg/L), lymphocyte, neutrophil, and neutrophil/lymphocyte (N/L) ratios were checked at the beginning and 7 th day of the study. Key results: A total of 44 patients with COVID-19 have completed this trial with vitamin D insufficiency in the baseline. The lymphocyte level increased while LDH (IU/ml), neutrophil level, and N/L ratio decreased after intervention with a high vitamin D dose, which was insignificant. The CRP (mg/L) and IL-6 (Pg/L) were significantly reduced after high-dose vitamin D intervention. Conclusions: Based on the results, the effect of high doses of vitamin D on inflammatory indices was significant in patients with COVID-19 hospitalized in the ICU.