Fischer Leslie M, daCosta Kerry Ann, Kwock Lester, Stewart Paul W, Lu Tsui-Shan, Stabler Sally P, Allen Robert H, Zeisel Steven H
Department of Nutrition, School of Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA.
Am J Clin Nutr. 2007 May;85(5):1275-85. doi: 10.1093/ajcn/85.5.1275.
Although humans require dietary choline for methyl donation, membrane function, and neurotransmission, choline can also be derived from the de novo synthesis of phosphatidylcholine, which is up-regulated by estrogen. A recommended Adequate Intake (AI) exists for choline; however, an Estimated Average Requirement has not been set because of a lack of sufficient human data.
The objective of the study was to evaluate the dietary requirements for choline in healthy men and women and to investigate the clinical sequelae of choline deficiency.
Fifty-seven adult subjects (26 men, 16 premenopausal women, 15 postmenopausal women) were fed a diet containing 550 mg choline x 70 kg(-1) x d(-1) for 10 d followed by <50 mg choline x 70 kg(-1) x d(-1) with or without a folic acid supplement (400 microg/d per randomization) for up to 42 d. Subjects who developed organ dysfunction during this diet had normal organ function restored after incremental amounts of choline were added back to the diet. Blood and urine were monitored for signs of toxicity and metabolite concentrations, and liver fat was assessed by using magnetic resonance imaging.
When deprived of dietary choline, 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage, whereas only 44% of premenopausal women developed such signs of organ dysfunction. Moreover, 6 men developed these signs while consuming 550 mg choline x 70 kg(-1) x d(-1), the AI for choline. Folic acid supplementation did not alter the subjects' response.
Subject characteristics (eg, menopausal status) modulated the dietary requirement for choline, and a daily intake at the current AI was not sufficient to prevent organ dysfunction in 19 of the subjects.
尽管人类需要膳食胆碱来进行甲基供体、维持膜功能和神经传递，但胆碱也可从磷脂酰胆碱的从头合成中获得，而雌激素可上调其合成。胆碱有推荐的适宜摄入量（AI）；然而，由于缺乏足够的人体数据，尚未设定估计平均需求量。
本研究的目的是评估健康男性和女性对胆碱的膳食需求，并研究胆碱缺乏的临床后果。
57名成年受试者（26名男性、16名绝经前女性、15名绝经后女性）先摄入含550 mg胆碱×70 kg⁻¹×d⁻¹的饮食10天，然后摄入低于50 mg胆碱×70 kg⁻¹×d⁻¹的饮食，部分受试者随机补充叶酸（400 μg/d），持续42天。在此饮食期间出现器官功能障碍的受试者，在饮食中添加递增剂量的胆碱后，器官功能恢复正常。监测血液和尿液中的毒性迹象和代谢物浓度，并使用磁共振成像评估肝脏脂肪。
当缺乏膳食胆碱时，77%的男性和80%的绝经后女性出现脂肪肝或肌肉损伤，而只有44%的绝经前女性出现此类器官功能障碍迹象。此外，6名男性在摄入胆碱的AI（550 mg胆碱×70 kg⁻¹×d⁻¹）时出现了这些迹象。补充叶酸并未改变受试者的反应。
受试者特征（如绝经状态）调节了对胆碱的膳食需求，按照当前AI的每日摄入量不足以预防19名受试者出现器官功能障碍。
