Choline is an essential nutrient that plays a role in normal cell function and transportation of nutrients through the body. Dietary sources include eggs, beef liver, chicken liver and wheat germ. However while an Adequate Intake level exists, of 550mg for men and 425mg for women, no Estimated Average Requirement has been set because of insufficient human data. The study, conducted at Penn State University and published this month in the American Journal of Clinical Nutrition, set out to evaluate healthy men and women's dietary requirements for choline, and look at the clinical consequences of choline deficiency. The study involves 57 subjects, of which 26 were men, 16 premenopausal women and 15 postmenopausal women. They received a diet containing 550mg choline for ten days, followed by less than 50mg for up to 42 days. When consuming less of the nutrient, 77 per cent of the men, 80 per cent of the post menopausal women, and 44 per cent of the premenopausal women showed fatty liver or muscle damage. Moreover, six of the men showed these signs even when they were consuming the 550mg of choline per day - the current AI for men. Nineteen per cent of subjects were found to need as much as 825mg of choline in order to avoid damage. The researchers said: "Subjects who developed organ dysfunction during this diet had normal organ function restored after incremental amounts of choline were added back to the diet." "These study results clearly indicate that some adults, notably men and post-menopausal women, need more choline than is recommended by the current AI," said co-author Kerry-Ann da Costa of the University of North Carolina. "We hope these findings will aid the Institute of Medicine in refining the Dietary Reference Intake for this nutrient." Source: The American Journal of Clinical Nutrition "Sex and menopausal status influence human dietary requirements for the nutrient choline". May 2007, Volume 85, No 5, Pages: 1275-1285 Authors: Leslie M Fischer, Kerry Ann daCosta, Lester Kwock., Paul W Strewart, Tsui-Shan Lu, Sally P Stabler, Robert H Allen and Steven H Zeisel.