MTHFR C677T genotype and choline intake affect choline dynamics in Mexican American men

Abstract

As part of a 12 wk controlled feeding study conducted in Mexican American men, stable isotope methodology was employed to assess the influence of choline intake and MTHFR C677T genotype on choline flux. Beginning wk 10, Mexican American men (15 677TT, 8 677CC) consumed 15% of either 550 or 1100 mg/d choline as D9‐choline. Liquid chromatography (or gas chromatography) mass spectrometry was used to measure the isotopic enrichment of choline and relevant metabolites in urine and blood (on‐going) obtained at wk 12. In urine, the enrichment of D6‐dimethylglycine to D9‐choline was greater (P<0.05) in men with the MTHFR 677TT vs CC genotype. In addition, enrichment of betaine was greater (P<0.05) in the 1100 vs the 550 mg/d choline intake group. These initial results suggest that choline flux through the betaine N‐methyltransferase pathway is greater in men with the MTHFR 677TT genotype relative to those with 677CC genotype under the conditions of this study. Further, oxidation of choline to betaine appears to be enhanced when choline intake is increased.Supported by the National Institutes of Health grant S06GM53933 and funds from the California Agricultural Research Initiative.