L-Threonine-d2 is intended for use as an internal standard for the quantification of L-threonine by GC- or LC-MS. L-Threonine is an essential amino acid.It undergoes catabolism via threonine dehydrogenase to yield the glucogenic metabolites succinyl coenzyme A (succinyl CoA) and pyruvate. Administration of L-threonine-deficient diets induces lameness of the thoracic and pelvic limbs and decreases food intake and weight gain in kittens.