Effect of High-Dose Vitamin D on Mortality and Hospital Length of Stay in ICU Patients with COVID-19: A Randomized Clinical Trial

Background: Evidence indicating the effect of vitamin D supplementation on improving the clinical outcomes of COVID-19 is limited. Objectives: This study aimed to examine the effect of high-dose vitamin D on mortality and hospital length of stay in ICU patients with COVID-19. Methods: A single-center, double-blind, placebo-controlled, randomized clinical trial study was conducted on 61 patients with moderate to severe COVID-19 hospitalized in the ICU of Golestan Hospital, Kermanshah, Iran. Participants were randomly divided to receive a single dose of 300 000 IU vitamin D3 intramuscularly (n = 31) or placebo (n = 30). The primary outcomes were the length of hospital stay and in-hospital mortality. Secondary outcomes were the length of stay in the ICU, the number of patients requiring mechanical ventilation, and the serum level of 25-hydroxyvitamin D. Results: Out of 61 randomized patients, 44 patients with a mean age of 53.49 ± 13.2 years, body mass index of 29.80 ± 5.0 kg/m², and serum vitamin D level of 24.36 ± 4.47 mg/dL were included in the study for primary analysis, of whom 31 (70.5%) cases were men. Median (interquartile range), the length of hospital stay between the vitamin D group (5.0 [6.0 - 11.0] days), placebo group (11.0 [6.0 - 17.0] days) (log-rank P = 0.23; unadjusted hazard ratio [HR] for hospital discharge, 3.4 [95% confidence interval [CI], 0.4 - 28.05]; P = 0.25; adjusted HR, 0.04 [95%CI, 11.52 - 0.0001]; P = 0.27) and mortality (unadjusted odds ratio [OR], 0.63 [95% CI,0.09 - 4.21]; P = 0.63; adjusted OR, 0.46 [95%CI, 0.03 - 6.55]; P = 0.57) showed no significant difference between the two groups before and after the adjustment of confounding factors. No significant difference was observed between the two groups regarding the need for mechanical ventilation (unadjusted OR for intubation = 2.1 [95% CI, 0.17 - 25.01]; P = 0.55), adjusted OR = 1.16 [95%CI, 0.04 - 27.57]; P = 0.92), and the length of stay in ICUs (log-rank = 2.49, P = 0.114; unadjusted HR for ICU discharge, 6.28 [95%CI, 0.5 - 78.42]; P = 0.15; adjusted HR = 21.48 [95%CI, 0.12 - 3677.48]; P = 0.24). Conclusions: Based on the results, A high dose of vitamin D did not significantly reduce mortality and hospital length of stay in ICU patients with COVID-19.