Little is known about the importance of choline in human nutrition nor are methods available for the diagnosis of choline deficiency. In animal experiments, ad-ministration of diets low in choline leads to deficiency which is characterized by accumulation of fat in the liver and hemorrhagic lesions of the kidney. Choline fun tions as an integral part of acetylcholine, as a source of labile methyl groups and in the formation of phospholipids. The dietary requirement of choline in animals or man is uncertain since this compound can be manufactured in the body and the need is dependent on other sources of methyl groups in the diet, such as methionine or betaine. Elvehjem suggested on the basis of animal studies that the human requirement is probably less than 500 mg. daily. The average diet contains about 250 to 600 mg. of choline.

Choline has been reported to be beneficial in the treatment of fatty liver and cirrhosis in man. It is difficult to evaluate such therapy since administration of choline has usually been only one aspect of a regimen which has included a diet high in protein and, in some instances, ad-ministration of methionine. Cornatzer and Cayer (39) found that the administration of a single 10.0 gm. dose of choline resulted in an increase in the rate of phospholipid turnover in subjects in whom fatty infiltration of the liver was demonstrated on initial biopsy. When fat was not present in the liver, this effect was not observed. Eckhardt and associates (39), in an investigation of subjects with active fatty alcoholic cirrhosis, reported that choline administration was followed by a moderate reduction in liver fat, as seen in biopsy specimens. The liver cell showed much greater improvement, however, when a diet adequate in protein was prescribed.

Choline, methionine, vitamin B12 and folic acid have been found to be interrelated in the prevention of fatty livers under certain dietary conditions in animals. Whether these findings are applicable to man is unknown.