A few amino acid defined formulas are shown below. This type of diet is used when a diet needs to be deficient in one or more amino acids, or adjustments need to be made to specific amino acid levels.
Formula examples:

• TD.99366????? Amino acid diet
• TD.90262????? Methionine?and choline deficient diet
• TD.00434????? Folic acid deficient diet
• TD.99386????? No lysine AA diet

Sometimes this type of diet is used to further reduce the background level of certain vitamins that are found in protein sources such as casein or vitamin-free (alcohol extracted) casein. Some folic acid deficient diets utilize this approach.
The amino acid profile for most amino acid defined diets is based on work by Harper and Rogers (J. Nutr. (1965) 87:267-276) and is not representative of the amino acid profile of an intact protein source such as casein. Other amino acid profiles can be specified. When an amino acid(s) is removed or reduced, isonitrogenous adjustment can be made if required.