doi:10.3390/ijms232012424engFeiner Solís, ÁngelaAvedillo Salas, AnaLuesma Bartolomé, María JoséSantander Ballestín, SoniaThe Effects of Vitamin D Supplementation in COVID-19 Patients: A Systematic ReviewART-2022-130790Vitamin D has an immune-modulating effect on respiratory tract infections. For this reason, it has been proposed as part of the treatment in COVID-19. Furthermore, vitamin D deficiency has been associated with worse clinical outcomes of this disease. The aim of this systematic review was to determine whether vitamin D supplementation modifies the disease course. Therefore, eleven studies involving randomised clinical trials are analysed, in which groups of COVID-19 patients with or without vitamin D supplementation as part of the treatment are compared. A control group was treated with best available therapy, and in some of the clinical trials, also with a placebo. According to the outcomes, it seems that patients benefit from receiving a daily or maintained in time vitamin D dose regardless of vitamin D serum levels at the beginning of the trial. The administration of a single vitamin D dose does not seem to have any effect on the health status of these patients. However, the outcomes are heterogeneous and larger clinical trials are necessary.2022http://zaguan.unizar.es/record/11986610.3390/ijms232012424http://zaguan.unizar.es/record/119866oai:zaguan.unizar.es:119866info:eu-repo/grantAgreement/ES/DGA/A05-20RInternational Journal of Molecular Sciences 23, 20 (2022), 12424 [15 pp.]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess