foods for special medical purposes for use in dietary management of "rare metabolic disorders", such as Maple Syrup Urine Disease (VIL), Homocystinuria (Met), Methylmalonic Aciduria and Propionic Aciduria (TVMI) or Tyrosinemia (TP) contain pure L-amino acids as protein source supplemented with vitamins, minerals and trace elements in age adapted amounts. This results in different ZERO-System products, each of them optimally suitable for a specific age group: Zero Infant for VIL, Met, TVMI or TP. All Infant Mix LCP products are intended for infants. Available soon.  ZERO-VIL-SYSTEM Kid, Junior and Advance free of Valine, Isoleucine and Leucine for the treatment of disorders in metabolism of branched chain amino acids, e.g. Maple Syrup Urine Disease (MSUD).  ZERO-MET-SYSTEM Kid, Junior and Advance free of Methionine for the treatment of Homocystinuira.  ZERO-TVMI-SYSTEM Kid, Junior and Advance free of Threonine, Valine, Methionine and Isoleucine for the treatment of organic acidurias. ZERO-TP-SYSTEM Kid, Junior and Advance free of Tyrosine and Phenylalanine for the treatment of Tyrosinemia. Each ZERO-SYSTEM consists of different products (except Zero Infant Mix LCP), which are different in energy content, preparation and taste, but interchangeable with each other. This easy interchange is made possible due to identical concentrations of micronutrients per gram protein equivalent in all products of the system.  All products within a specific ZERO-SYSTEM may be combined with each other during the day. Ask your metabolic centre for an optimal combination.