"Dietary shortages of crucial minerals like zinc may be keeping almost a third of the world's people from optimizing their immune system. Research shows that adequate zinc intake reduces the severity and duration of illness caused by the common cold.
Experts say as many as two billion people around the world have diets deficient in zinc - and studies at Oregon State University and elsewhere are raising concerns about the health implications this holds for infectious disease, immune function, DNA damage and cancer.
The common cold places a heavy burden on society, accounting for approximately 40% of time taken off work and days of school missed by children each year. The idea that zinc might be effective against the common cold first came from a study carried out in 1984, which showed that zinc lozenges could reduce how long symptoms lasted."