Threonine (abbreviated as Thr or T) is an a-amino acid

As an essential amino acid, it is not synthesized by the body and must be obtained from food sources.

Foods high in threonine include cottage cheese, poultry, fish, meat, lentils, and sesame seeds.

References

IUPAC-IUBMB Joint Commission on Biochemical Nomenclature. Nomenclature and Symbolism for Amino Acids and Peptides. Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc. Retrieved on 2007-05-17.