Zinc

Zinc is involved in immune function, wound healing, taste and smell, and making proteins and DNA. Good food sources include meat, shellfish, pulses, seeds, nuts and dairy products.

Most people who eat a varied diet get enough zinc, though intake can be lower on very restricted or plant-only diets. Some studies suggest zinc lozenges may slightly shorten a cold, but the evidence is mixed and they can cause nausea or an unpleasant taste.

Taking more zinc is not better. High doses over a long time can interfere with copper levels and cause problems, so stay within the amounts on the label and speak to a clinician or pharmacist before long-term use, especially if you take other medicines.