C14 Tetradecanoyl

C14 Tetradecanoyl measures the amount of tetradecanoylcarnitine, a long-chain acylcarnitine, in your blood. Acylcarnitines form when fatty acids are linked to carnitine so they can be carried into mitochondria, the part of cells that helps make energy.

This measurement is usually part of an acylcarnitine profile performed by tandem mass spectrometry. Your clinician may order it to evaluate how your body handles long-chain fats, especially if a newborn screen or clinical symptoms suggest a problem with fatty acid oxidation.

Changes in C14 can point toward conditions that affect long-chain fatty acid oxidation, such as very long-chain acyl-CoA dehydrogenase deficiency or related transport and oxidation defects. These conditions can lead to low energy, muscle pain, or stress on the heart or liver during illness or when you have not eaten for a while.

Looking at C14 together with other acylcarnitines helps guide next steps, monitoring, and treatment planning. The test is used to follow up abnormal newborn screening results, during metabolic evaluations for symptoms, and to monitor response to diet changes, carnitine use, and strategies that reduce metabolic stress.

Results are interpreted alongside age, symptoms, feeding status, and the pattern of other acylcarnitines. A single value on its own is not diagnostic. Mild shifts can occur in healthy people, in premature infants, or during intercurrent illness.

If your result is higher than expected, your provider may repeat the test, review a full acylcarnitine profile, and order related studies such as free and total carnitine, urine organic acids, acylglycines, or genetic testing. If results are unexpectedly low or inconsistent, timing of the sample, supplements, and medications are reviewed. A metabolic specialist may be involved to confirm a diagnosis and to plan care.