Zinc is a mineral that is needed for the absorptions of minerals across the cell wall. With low zinc, you cannot absorb properly. We are not only 'what we eat' we are 'what we absorb'.
A zinc tally test is easy and inexpensive. We take a bit of liquid zinc, have you hold it in your mouth for 10 seconds. If it taste metallic - you have sufficient stores of zinc. If it doesn't taste at all - you are deficient.
Most folks are deficient and I recommend supplements. It takes a along time to build up the stores. We adjust your diet during that time to increase the zinc supply in your food.
Our food in today's world does not have the mineral content and if we are deficient, organic food concentrates are useful supplements to make sure we maintain optimal health.