Threonine

Threonine is an essential amino acid, one of the building blocks your body uses to make proteins. Because your body cannot make it on its own, you must get threonine from food or nutrition support. A threonine test measures the amount of this amino acid in blood or in urine.

Clinicians use threonine measurements as part of an amino acid evaluation to look at nutrition status and how your body processes proteins. It can help assess for inborn errors of metabolism, monitor specialized diets or nutrition therapy, and provide clues in liver or kidney conditions that affect amino acid handling.

Abnormal threonine levels can point to issues with protein intake, absorption, or breakdown. High or low values may be seen with metabolic disorders, inadequate or excessive protein intake, malabsorption, or liver dysfunction. In infants and children, amino acid testing is often used when there are concerns for inherited metabolic conditions, poor growth, unexplained illness, or abnormal newborn screening.

Your clinician may order threonine with a broader amino acid profile to see patterns that suggest a specific condition. Results can guide next steps such as dietary adjustments, genetic testing, or treatment by a metabolic specialist or dietitian. Tracking levels over time can also help monitor how well a nutrition plan or therapy is working.

Your result is interpreted in the context of your age, sample type, diet, and other amino acid values. A single high or low value is not a diagnosis. Your clinician will consider whether you were fasting, whether you recently had protein supplements or nutrition support, and whether you were ill at the time of collection.

If threonine is higher than expected, your team may review your diet and medications, look for liver or kidney issues, and consider additional metabolic testing. If it is lower than expected, they may check for poor intake, malabsorption, or increased needs during illness or growth. Follow‑up can include repeating the test under standardized conditions, reviewing a full amino acid profile, or consulting a metabolic specialist or dietitian to tailor nutrition and further evaluation.