HOMOCYSTEINE INCREASES AS FOLATE DECREASES IN PLASMA OF HEALTHY-MEN DURING SHORT-TERM DIETARY-FOLATE AND METHYL-GROUP RESTRICTION
HOMOCYSTEINE INCREASES AS FOLATE DECREASES IN PLASMA OF HEALTHY-MEN DURING SHORT-TERM DIETARY-FOLATE AND METHYL-GROUP RESTRICTION
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DOI：
10.1093/jn/124.7.1072
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发表时间：
1994-07-01
影响因子：
4.2
通讯作者：
SWENDSEID, ME
中科院分区：
文献类型：
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作者：
JACOB, RA;WU, MM;SWENDSEID, ME
10名健康成年男性被喂食低叶酸和外源性甲基的饮食，以研究对叶酸需要量和状态的影响。在整个108天的研究中，这些人被安置在一个代谢单位。在9天的基线期（P1）后，这些人被喂食氨基酸定义的大豆产品饮食45天，其中提供25 μ g/d的叶酸30天（P2）和（与叶酸补充剂）99 μ g/d的15天（P3）。在P2和P3，低蛋氨酸和胆碱饮食补充蛋氨酸的一半的科目，以改变膳食甲基摄入量。然后在接下来的54天（P4-P6）重复这些阶段，并在P5和P6中交叉蛋氨酸摄入。限制膳食甲基摄入量并没有增加膳食叶酸的需要量。血浆总同型半胱氨酸在叶酸消耗过程中上升，并与血浆叶酸呈负相关;然而，同型半胱氨酸对叶酸摄入量变化的反应在个体之间从非常强到不存在。结果支持先前的建议，血浆同型半胱氨酸浓度增加提供了功能性叶酸缺乏症的标志物，并进一步表明，由于叶酸摄入量低，个体对高同型半胱氨酸血症的易感性可能存在很大差异。通过叶酸补充期间高同型半胱氨酸浓度缺乏正常化判断，目前成年男性的叶酸RDA可能无法提供预期的保护范围。
Ten healthy adult men were fed a diet low in folate and exogenous methyl groups to study the effects on folate requirement and status. The men were housed in a metabolic unit for the entire 108-d study. After a 9-d base-line period (P1), the men were fed an amino acid-defined soybean product diet for 45 d, which provided 25 mu g/d of folate for 30 d (P2) and (with a folate supplement) 99 mu g/d for 15 d (P3). During P2 and P3, the low methionine and choline diet was supplemented with methionine for half the subjects to vary the dietary methyl group intake. The periods were then repeated over the next 54 d (P4-P6), with a cross-over of methionine intakes in P5 and P6. Restricting dietary methyl group intake did not increase the dietary folate requirement. Plasma total homocysteine rose during folate depletion and correlated inversely with plasma folate; however, the response of homocysteine to changes in folate intake varied among individuals from very strong to absent. The results support previous suggestions that increased plasma homocysteine concentrations provide a marker of functional folate deficiency, and further indicate that individuals may differ greatly in their susceptibility to hyperhomocysteinemia due to low folate intakes. Judged by the lack of normalization of high homocysteine concentrations during folate repletion, the current folate RDA for adult men may not provide the expected margin of protection.