A recent review illustrated that vitamins A and D showed a potential benefit in deficient populations. In viral respiratory infections, zinc and selenium (trace elements) have also demonstrated favorable immune-modulatory effects. Several probiotics and nutraceuticals may also have some role in enhancing immune functions. In the nutritionally depleted elderly population, micronutrients may be beneficial.

Evidence from previous clinical trials that examined nutrition-based interventions for viral disorders (with particular emphasis on respiratory infections) was determined. It also aimed to yield a summary of possible benefits of nutraceuticals, some vitamins, trace elements, and probiotics in viral infections.

A systematic literature search strategy utilizing keywords was conducted in three medical databases: PubMed, Web of Science, and SciVerse Scopus. Initially, 640 records were recognized. From other sources, a total of 22 studies were included. After excluding articles that did not fulfill the inclusion criteria and duplicate articles, 43 studies were procured.

Approximately 1/5 of the world’s population is at inadequate zinc intake risk, therefore supplementation of 20mg/daily zinc is advocated for optimal immune function. especially For vulnerable populations such as the elderly, elective micronutrient supplementations may be valuable.

During the COVID-19 pandemic, patients with malnutrition, diabetes, and obesity require personalized nutrition advice to protect their health. Among trace elements, 150 mg/daily zinc and 200 mg/daily selenium supplementation may improve your immunity. Thus, nutrition principles based on these data may be beneficial in COVID-19 prevention and management.