The common cold is generally characterized by acute inflammation of the nose, sinuses, pharynx, and larynx mainly because of viral infection. Episodes of cold are usually mild and do not develop to serious health problems such as pneumonia or bacterial infections, nor does it require hospitalization. But the high morbidity of this infection, which accounts for 20% of medical visits in developed countries has caused significant socioeconomic burden by adversely affecting daily activity, productivity, and attendance from school or work.

The effect of vitamin C on prevention of common cold in healthy adults is investigated broadly, but not that of any other micronutrients. The objective of this analysis is to evaluate the effects of providing micronutrients singly by orally on cold occurrence, and/or management of cold duration and symptom severity in healthy adults from systematically searched controlled randomized trials.

660 identified studies were screened from four electronic databases and data were extracted from 20 studies. The quality of the selected studies was evaluated by using the Cochrane risk of bias tool. The certainty in the results was evaluated with the Grading of Recommendations Assessment, Development and Evaluation approach. The review discovered that micronutrients supplementation, except for vitamin C, might not prevent cold occurrence or reduce symptom severity in healthy adults. But zinc supplementation when given singly was observed to potentially decrease the cold duration by 2.25 days. This outcome suggested that zinc supplementation might decrease the overall burden owing to common cold in healthy adults.

Source: Wang MX, Win SS, Pang J. Zinc Supplementation Reduces Common Cold Duration among Healthy Adults: A Systematic Review of Randomized Controlled Trials with Micronutrients Supplementation. Am J Trop Med Hyg. 2020 Jul;103(1):86-99. doi: 10.4269/ajtmh.19-0718. Epub 2020 Apr 23. PMID: 32342851; PMCID: PMC7356429.