Choline intakes at AI levels are sufficient in preventing liver dysfunction in Mexican American men but are not optimal in minimizing plasma total homocysteine increases after a methionine load

This controlled feeding study investigated the influence of choline intake ranging from 300 to 2200mg/d on biomarkers of choline status. Mexican American men (n=60) differing in methylenetetrahydrofolate reductase (MTHFR) C677T genotype (29 677TT, 31 677CC) consumed a diet providing 300mg/d choline plus supplemental choline intakes of 0, 250, 800 or 1900 mg/d for total choline intakes of 300, 550 (choline AI), 1100 or 2200mg/d, respectively for 12‐wk; 400mcg/d as dietary folate equivalents and 173mg/d betaine were consumed throughout the study. Plasma choline and betaine increased (P<0.05) in response to 550, 1100 and 2200mg/d choline (2200>1100=550) whereas no change was observed on the 300mg/d group. Plasma phosphatidylcholine declined (P<0.05) in response to 300mg/d possibly due to declining folate status; no changes were observed in the other choline intake groups. After a methionine load, choline intakes of 1100 and 2200 mg/d groups attenuated (P<0.006) the rise in plasma tHcy relative to the 300 and 550 mg/d groups. No changes in plasma ALT or AST concentrations were detected regardless of choline intake. These data suggest that 550 mg/d choline is sufficient to prevent liver dysfunction in this population; higher intakes are needed to optimize other measured end‐points. Supported by NIH Grant #S06GM053933.