This discussion emphasizes that nutrition is an important factor, influencing the general health and tissue tolerance of orthodontic patients on many levels. While orthodontists will rarely see frank manifestations of nutritional deficiencies, it should be recognized that suboptimal levels of certain nutrients are common and have an effect on the biologic responses of the tissues influenced by orthodontic treatment. Additionally, the age group typically involved in orthodontic treatment has particularly high nutritional demands and particularly poor dietary behavior.