Biomarkers of nutrient exposure and status in one-carbon (methyl) metabolism
Biomarkers of nutrient exposure and status in one-carbon (methyl) metabolism
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DOI：
10.1093/jn/133.3.941s
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发表时间：
2003-03-01
影响因子：
4.2
通讯作者：
Mason, JB
中科院分区：
文献类型：
--
作者：
Mason, JB
一碳代谢是相互关联的生化反应的网络，涉及一碳基团从一种化合物转移到另一种化合物。其中一些反应所需的辅酶包括 B 族维生素、叶酸、维生素 B-12、维生素 B-6 和核黄素（维生素 B-2），而该方案中重要的中间化合物包括蛋氨酸和胆碱。在过去的几年里，人们对一碳代谢重新产生了兴趣，最近的见解表明，上述营养素的适度饮食不足，其程度不足以引起经典的缺乏综合症，仍然可能导致重要的疾病，如神经管缺陷、心血管疾病和癌症。通过食物频率问卷评估营养暴露以及通过血浆和尿液维生素测定评估营养状况的传统方法具有一定的有效性和实用性。评估适当的中间化合物（例如叶酸的血浆同型半胱氨酸和维生素 B-12 的甲基丙二酸）的浓度可以提供进一步的见解，因为它们似乎增加了更传统的测定所不存在的一定程度的灵敏度。制定整合所有这些营养素的状态并将其表达为个体功能性“甲基化能力”的措施也可能具有价值。 S-腺苷甲硫氨酸和S-腺苷高半胱氨酸的血浆或组织浓度以及基因组DNA甲基化是这方面的两个潜在候选者，尽管还需要做很多工作来确定这些关系的性质。
One-carbon metabolism is a network of interrelated biochemical reactions that involve the transfer of one-carbon groups from one compound to another. The coenzymes necessary for several of these reactions include the B-vitamins, folate, vitamin B-12, vitamin B-6 and riboflavin (vitamin B-2), whereas important intermediary compounds in this schema include methionine and choline. There has been renewed interest in one-carbon metabolism during the past several years, engendered by recent insights that indicate that modest dietary inadequacies of the abovementioned nutrients, of a degree insufficient to cause classical deficiency syndromes, can still contribute to important diseases such as neural tube defects, cardiovascular disease and cancer. Traditional means of assessing nutrient exposure with food frequency questionnaires, and nutrient status with plasma and urine vitamin assays, has some genuine validity and utility. Assessing the concentration of appropriate intermediary compounds, such as plasma homocysteine for folate and methylmalonic acid for vitamin B-12, provides further insights because they appear to add a degree of sensitivity that does not exist with the more traditional assays. There may also be value in developing measures that integrate the status of all these nutrients and express it as a functional "methylation capacity" of the individual. Plasma or tissue concentrations of S-adenosylmethionine and S-adenosylhomocysteine, and genomic DNA methylation are two potential candidates in this regard although much work is yet to be done to define the nature of these relationships.