Minerals are vital nutrients that the body cannot produce itself and must therefore take in through food. They have different functions in the body depending on the mineral. Many minerals are involved in building bones, teeth, hormones and blood cells. They also help the body to maintain its water balance and are important in the conduction of impulses via the nerves. Minerals are found in plant and animal foods, and vegetables and whole grain products in particular help to meet the body's needs. Depending on which mineral is lacking in the body, different symptoms can occur. Some examples are impaired concentration and performance, sleep disorders, skin and mucous membrane changes, tooth decay or digestive disorders. Minerals are divided into bulk elements and trace elements.