[header] How to choose vitamins and supplements to prevent flu [title] Try taking zinc syrup or lozenges. [step] Zinc has long been believed to have immune boosting properties. Research on the precise effectiveness of zinc has produced mixed results, but zinc may be able to reduce the likelihood of becoming sick. 
If it is safe for you to take zinc given your current health and any existing medications, taking zinc in the form of syrup or lozenges may reduce your risk of contracting the flu. [substeps] It's best to take zinc in the form of lozenges and syrups.