One of my favorite trivia questions: What is the only rock humans eat? If you guessed salt, you would be right. If you eat other kinds of rocks or clay, psychiatrists get involved and they would say you are suffering from geophagia. But while we only non-pathologically eat one kind of rock, we do consume a lot of minerals and trace elements, like calcium, magnesium, copper, and iron. And we also need zinc.
Zinc does some important heavy lifting in the body, it is required for hundreds of enzymes to work, it influences DNA expression, it is important in the nervous system moderating neuronal excitability and brain plasticity and so is important for learning. When zinc binds with dopamine transporters it can influence dopamine reuptake which is also important for learning.
But does zinc help with immunity? For a long time, the answer has been a qualified maybe but recently a meta-analysis has concluded that, yes, zinc does help with the common cold.
As Therapy: Zinc supplementation seems to shorten the duration of the common cold by about a day and lessen the severity of the infection by about 40% which is considered a small to moderate effect.
As Prevention: Another pool of studies found that subjects who received a placebo suffered about 3.15 colds a year whereas the subjects who were supplementing with zinc suffered from 1.3 colds per year.
This is why we add zinc to Support System VZ herbal capsules - the Z is for zinc. Every little bit of advantage you can get can help your body fight off colds and flus. But, as a wise old doctor told me once, nothing you take fights infections, only your body fights infections, everything else is support for your immune system. So we add the zinc and we add the D3 and we add the Vitamin C but we also strongly encourage hand washing and when appropriate mask wearing.