TheRoleofImmunomodulatoryNutrientsin AlleviatingComplicationsRelatedtoSARS-CoV-2: AScopingReview

Abstract

The recent coronavirus disease 2019 (COVID-19) pandemic has warranted the need to investigate potential therapies or prophylaxis against this infectiousrespiratorydisease.ThereisemergingevidenceaboutthepotentialroleofnutrientsonCOVID-19inadditiontousingmedicationssuchas hydroxychloroquineandazithromycin.Thisscopingreviewaimstoexploretheliteratureevaluatingtheeffectofimmunomodulatorynutrientson theoutcomesincludinghospitalization,intensivecareunitadmission,oxygenrequirement,andmortalityinCOVID-19patients.Aliteraturesearch of databases including Medline, EMBASE, CINAHL, Web of Science, Cochrane, Scopus, and PubMed, as well as hand-searching in Google Scholar (upto10February2021)wasconducted.Allhumanstudieswithdifferentstudydesignsandwithoutlimitationonpublicationyearwereincluded except for non-English-language and review articles. Overall, out of 4412 studies, 19 met our inclusion criteria. Four studies examined the impact of supplementation with vitamin C, 4 studies – zinc, 8 studies – vitamin D, and 3 studies investigated the combination of 2 (zinc and vitamin C) or3(vitaminD,vitaminB-12,andmagnesium)nutrients.Althoughlimiteddataexist,availableevidencedemonstratedthatsupplementationwith immune-supportivemicronutrientssuchasvitaminsDandCandzincmaymodulateimmunityandalleviatetheseverityandriskofinfection.The effectiveness of vitamin C, vitamin D, and zinc on COVID-19 was different based on baseline nutrient status, the duration and dosage of nutrient therapy, time of administration, and severity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease. This review indicated thatsupplementationwithhigh-dosevitaminC,vitaminD,andzincmayalleviatethecomplicationscausedbyCOVID-19,includinginflammatory markers,oxygentherapy,lengthofhospitalization,andmortality;however,studiesweremixedregardingtheseeffects.Furtherrandomizedclinical trialsarenecessarytoidentifythemosteffectivenutrientsandthesafedosagetocombatSARS-CoV-2