Folate nutriture alters choline status of women and men fed low choline diets
Folate nutriture alters choline status of women and men fed low choline diets
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DOI：
10.1093/jn/129.3.712
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发表时间：
1999-03-01
影响因子：
4.2
通讯作者：
Swendseid, ME
中科院分区：
文献类型：
--
作者：
Jacob, RA;Jenden, DJ;Swendseid, ME
胆碱和叶酸共享甲基化途径，并且在大鼠的研究中显示出代谢相互关联。为了确定人类胆碱状态是否与叶酸摄入量有关，我们在两项独立的代谢单位研究中测量了11名健康男性（33-46岁）和10名健康女性（49-63岁）的控制叶酸消耗和补充对血浆胆碱和磷脂酰胆碱浓度的影响。叶酸消耗4-5周后，通过补充低叶酸（男性和女性分别为25和56 μ g/d）和低胆碱（男性和女性分别为238和147 mg/d）饮食2-6周的蝶酰谷氨酸，改变叶酸的总摄入量。低叶酸/胆碱摄入导致亚临床叶酸缺乏;男性和女性的平均血浆胆碱分别降低28%和25%;男性的血浆磷脂酰胆碱降低26%（P < 0.05）。通过血清转氨酶和脂质浓度测定，未发生功能性胆碱缺乏症。在中度叶酸补充后，胆碱状态测量值的降低恢复到基线或更高，并且对叶酸补充的反应比血浆叶酸和同型半胱氨酸更敏感。给男性喂食蛋氨酸补充剂并不能阻止血浆胆碱消耗，这表明叶酸是这些甲基化途径的限制性营养素。结果表明：（1）叶酸摄入量低时，胆碱被用作甲基供体;（2）叶酸和胆碱摄入量低时，磷脂酰胆碱的从头合成不足以维持胆碱状态;（3）叶酸摄入量低时，成年人需要> 250 mg/d的膳食胆碱来维持血浆胆碱和磷脂酰胆碱。
Choline and folate share methylation pathways and, in studies of rats, were shown to be metabolically inter-related. To determine whether choline status is related to folate intake in humans, we measured the effect of controlled folate depletion and repletion on the plasma choline and phosphatidylcholine concentrations of 11 healthy men (33-46 y) and 10 healthy women (49-63 y) fed low-choline diets in two separate metabolic unit studies. Total folate intake was varied by supplementing low folate (25 and 56 mu g/d for men and women, respectively) and low choline (238 and 147 mg/d for men and women, respectively) diets with pteroylglutamic acid for 2-6 wk following folate-depletion periods of 4-5 wk. The low folate/choline intakes resulted in subclinical folate deficiencies; mean plasma choline decreases of 28 and 25% in the men and women, respectively; and a plasma phosphatidylcholine decrease of 26% in the men (P < 0.05). No functional choline deficiency occurred, as measured by serum transaminase and lipid concentrations. The decreases in choline status measures returned to baseline or higher upon moderate folate repletion and were more responsive to folate repletion than plasma folate and homocysteine. Feeding methionine supplements to the men did not prevent plasma choline depletion, indicating that folate is a more limiting nutrient for these methylation pathways. The results indicate that I) choline is utilized as a methyl donor when folate intake is low, 2) the de novo synthesis of phosphatidylcholine is insufficient to maintain choline status when intakes of folate and choline are tow, and 3) dietary choline is required by adults in an amount > 250 mg/d to maintain plasma choline and phosphatidylcholine when folate intake is low.