Vitamin D is essential for the function of immune system, and vitamin D deficiency is associated with higher incidence of respiratory infections. Since the beginning of the COVID-19 epidemic, vitamin D is proposed as a potential therapeutic solution to reduce mortality and severity of the disease. First results of vitamin D supplementation in patients hospitalized for COVID-19 have just been published.

The study was randomized and controlled. 76 patients have been enrolled. All received the best available therapy. In addition, 50 patients received calcifediol (25-hydroxy vitamin D, 0.532 mg on admission, and 0.266 mg on days 3 and 7, and then weekly until discharge or intensive care unit (ICU) admission), whereas 26 other patients received no supplement.

Results showed a lower rate of ICU admission in supplemented patients (2% vs. 50%, p < 0.001). Estimated odd ratio for ICU admission was 0.02 (95% CI: 0.002-0.17). Therefore, vitamin D, provided as 25-hydroxy vitamin D, is effective to reduce the severity of COVID-19 and to reduce the need of ICU admission.

Entrenas Castillo M, Entrenas Costa LM, Vaquero Barrios JM, Alcalá Díaz JF, López Miranda J, Bouillon R, Quesada Gomez JM. “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”. J Steroid Biochem Mol Biol. 2020 Oct;203:105751.