humans need a little bit of zinc to help their body run well. if they do not get enough zinc in their food, they can get a mineral deficiency. almost two billion people have a zinc deficiency. zinc deficiency makes one more easily get infections. some people say that when we get colds, we should take more zinc. others say that zinc does not make a difference. there are medicines that one can use when they have a cold. people add tiny amounts of zinc compounds to vitamin pills and cereals to make sure that they get enough zinc. most single-tablet vitamins have zinc in them. zinc is found in at least 100 enzymes. it is the second most common transition metal other than iron. zinc also is used by the brain. the human body contains 2 to 4 grams of zinc. a zinc enzyme helps remove carbon dioxide from blood. whole wheat has much zinc in it.