Method(s): LC-MS/MS (1).
What is measured: alfa-tocopherol (aToc), alfa-tocopherolacetate and gamma-tocopherol (gToc).
Performance of the assay
Lower limit of detection (LOD) (aToc/gToc): <0.005 µmol/L.
Within-day CV (aToc/gToc): 2-4/7 %; between-day CV: 4-5/8 %.
Assessment of vitamin E status.
Specimen, collection and processing
Patient/subject: Over night fasting is recommended.
Matrix: Serum or EDTA plasma.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Serum gel tubes must not be used. Samples should be put on ice, and protected from light.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values (aToc/gToc): 23-46/0.9-8.7 µmol/L.
Intraclass correlation coefficient (ICC) (aToc/gToc): 0.85/na.
1. Midttun, Ø., McCann, A., Aarseth, O., Krokeide, M., Kvalheim, G., Meyer, K., and Ueland, P.M. (2016). Combined measurement of 6 fat-soluble vitamins and 26 water-soluble functional vitamin markers and amino acids in 50 μL of serum or plasma by high-throughput mass spectrometry. Anal Chem 88, 10427-436.