Synonym: Glycine betaine, trimethylglycine.
Method(s): LC-MS/MS (1).
What is measured: Betaine (glycine betaine).
Performance of the assay
Lower limit of detection (LOD): 0.5 µmol/L.
Within-day CV: 6-7 %; between-day CV: 8-10 %.
Assessment of one-carbon status. Studies on folate status should include measurement of circulating betaine, which has been shown to serve as an alternative methyl donor in pregnant women (2) and middle aged men and women (3), in particular in subjects with low folate status.
Specimen, collection and processing
Patient/subject: Prandial status affects the concentration, which increases 10-15 % after a meal. The subjects should be fasting.
Matrix: EDTA plasma and serum.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Betaine is fairly stable. The blood sample should be centrifuged and the plasma/serum fraction put on ice, and frozen.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 15-51 µmol/L. The concentration is 20 % higher in men than in women.
Intraclass correlation coefficient (ICC) : 0.65.
1. Midttun, O., Kvalheim, G., and Ueland, P.M. (2013). High-throughput, low-volume, multianalyte quantification of plasma metabolites related to one-carbon metabolism using HPLC-MS/MS. Anal Bioanal Chem 405, 2009-017.
2. Fernàndez-Roig, S., Cavallé-Busquets, P., Fernandez-Ballart, J.D., Ballesteros, M., Berrocal-Zaragoza, M.I., Salat-Batlle, J., Ueland, P.M., and Murphy, M.M. (2013). Low folate status enhances pregnancy changes in plasma betaine and dimethylglycine concentrations and the association between betaine and homocysteine. Am J Clin Nutr 97, 1252-59.
3. Holm, P.I., Ueland, P.M., Vollset, S.E., Midttun, O., Blom, H.J., Keijzer, M.B.A.J., and denHeijer, M. (2005). Betaine and folate status as cooperative determinants of plasma homocysteine in humans. Arterioscler Thromb Vasc Biol 25, 379-385