Platform
Company
Metabolic Disorders
Review status
Currently under review
Pending specialist review and validation.
This test measures the amount of carnitine in your blood, reported as total carnitine. Carnitine is a nutrient that helps move long‑chain fatty acids into mitochondria, where your body turns fat into energy. It is obtained from food and also made in small amounts by the liver and kidneys.
Clinicians use this measurement to understand your overall carnitine status. It may be ordered alone or along with an acylcarnitine profile to assess energy metabolism, especially when there are concerns about inherited metabolic conditions or when monitoring carnitine supplementation.
Healthy carnitine levels support heart, muscle, and liver function, particularly during fasting, illness, or exercise when your body relies more on fat for energy. Low levels can be seen in inherited transport problems, poor intake, kidney or liver issues, or from certain medicines. High levels can occur with supplementation or reduced clearance.
Doctors order this test for symptoms like low energy, low blood sugar during illness, muscle weakness, or heart problems, and in newborn screening follow‑up. It is also used to monitor people receiving carnitine therapy, those on dialysis, or people taking medicines known to affect carnitine balance.
Your clinician will interpret the result in the context of your age, health history, diet, and any supplements or medicines you take. A lower‑than‑expected result may prompt additional testing such as separate free and acylcarnitine measurements, acylcarnitine profiling, urine organic acids, and sometimes genetic testing to look for specific transport or metabolic conditions. If a medicine is contributing, your care team may adjust therapy or add supplementation.
A higher‑than‑expected result can reflect recent carnitine supplementation or changes in how your body clears carnitine. In most cases, your clinician will review dosing, kidney function, and other labs. You may be asked about how and when the sample was collected, and whether you were fasting or taking supplements. Follow‑up plans are individualized and may include repeating the test, adjusting supplements, or coordinating care with a metabolic specialist.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Recent intake of L‑carnitine supplements or a high‑meat diet can raise blood carnitine, while strict vegetarian or very low‑protein diets may lower it. Tell your clinician what you eat and any over‑the‑counter products you use.
Valproic acid, pivalate‑containing antibiotics, and some anticonvulsants can lower carnitine levels, while carnitine therapy increases them. Always share a current medication list before testing.
Kidneys help conserve carnitine. Kidney disease or dialysis can alter levels, and liver disease can reduce the body’s production, affecting results and interpretation.
Intercurrent illness, prolonged fasting, or intense exercise shifts energy use toward fat, which can change carnitine distribution between blood and tissues and influence the result.
Newborns, infants, and pregnant individuals have different carnitine needs and handling. Reference targets and follow‑up plans may differ for these groups.
Levels can differ between dried blood spot and plasma, and timing relative to supplements or dialysis matters. Follow collection instructions and note when your last dose was taken.
References