Choline, an essential nutrient for humans.

摘要: Choline is required to make essential membrane phospholipids. It a precursor for the biosynthesis of neurotransmitter acetylcholine and also an important source labile methyl groups. Mammals fed choline-deficient diet develop liver dysfunction; however, choline not considered nutrient in humans. Healthy male volunteers were hospitalized semisynthetic devoid supplemented with 500 mg/day 1 wk. Subjects randomly divided into two groups, one that continued receive (control), other received no (deficient) three additional During 5th wk study all subjects choline. The contained adequate, but excess, methionine. In group, plasma phosphatidylcholine concentrations decreased average 30% during 3-wk period when was ingested; erthrocyte 15%; such changes occurred control group. serum alanine aminotransferase activity increased steadily from mean 0.42 mukat/liter 0.62 change Other tests renal function unchanged both groups study. Serum cholesterol 15% deficient group did humans consuming 3 had depleted stores tissues developed signs incipient dysfunction. Our observations support conclusion excess methionine folate are available diet.