Inborn errors of metabolism are inherited disorders in which the body cannot metabolize the components of food (carbohydrates, proteins, and
fats). Metabolism is the biochemical process that changes food components into energy and other required molecules. These disorders may be caused by the altered activity of essential enzymes, deficiencies of the substances that activate the enzymes, or faulty transport compounds. Metabolic disorders can be devastating if appropriate treatment is not initiated promptly and monitored frequently.
Inborn errors of metabolism often require diet changes, with the type and extent of the changes dependant on the specific metabolic disorder. The particular enzyme absence or inactivity for each inborn error of metabolism dictates which components are restricted and which are supplemented. Registered dietitians and physicians can help an individual assess the diet changes needed for each disease. The goals of nutrition therapy are to correct the metabolic imbalance and promote growth and development by providing adequate nutrition, while also restricting (or supplementing) one or more nutrients or dietary components. Additional goals in some disorders include reducing the risk of brain damage, other organ damage, episodes of metabolic crisis and coma, and even death. These restrictions and supplementations are specific for each disorder, and they may include the restriction of total fats, simple sugars, or total carbohydrates.
Listed below are several of the metabolic disorders that respond to nutrition therapy. The appropriate dietary restrictions and modifications that are necessary for treatment are also listed.
Patricia D. Thomas, The Gale Group Inc., Macmillan Reference USA, New York,