COVID-19 patients with Vitamin D treatment significantly reduced the chances of ICU admission comparing to the non-treatment group.

A parallel pilot randomized open-label, double-masked clinical trial of 76 patients hospitalized with COVID-19 infection reported that 50 patients treated with 25 hydroxy Vitamin D, only one required admission to the ICU (2%), while 13 (50%) of 26 untreated patients were admitted to the ICU.

Castillo, M. E., Entrenas Costa, L. M., Vaquero Barrios, J. M., Alcalá Díaz, J. F., Miranda, J. L., Bouillon, R., & Quesada Gomez, J. M. (2020). "Effect of Calcifediol Treatment and best Available Therapy versus best Available Therapy on Intensive Care Unit Admission and Mortality Among Patients Hospitalized for COVID-19: A Pilot Randomized Clinical study". The Journal of Steroid Biochemistry and Molecular Biology, 105751.

doi:https://doi.org/10.1016/j.jsbmb.2020.105751