由于各种感知和真正的健康益处,单个氨基酸作为补充剂广泛流行。目前,由于缺乏良好的人体剂量反应试验,国家卫生机构没有针对氨基酸的可耐受高摄入量(UL)提出建议。在过去的十年中,在国际氨基酸科学理事会(ICAAS)的倡议下,非营利组织,进行了一系列UL人体临床研究。这篇叙述性综述的目的是总结对6种必需氨基酸(亮氨酸,色氨酸,蛋氨酸,赖氨酸,组氨酸,苯丙氨酸),两种非必需氨基酸(精氨酸,丝氨酸)和两个非蛋白质氨基酸(鸟氨酸,瓜氨酸)并提供第一组UL。UL的膳食参考摄入量(DRI)框架的概念的简要背景,氨基酸UL的概念,并提供了结果的观点。数据表明,在相对健康的成人个体中,所测试的氨基酸具有良好的耐受性,和ULs,或未观察到的不良反应水平(NOAEL),可以确定最低观察到的不良反应水平(LOAEL)。ULs用于亮氨酸青年(35g/d),色氨酸(4.5g/d)和亮氨酸老年(30g/d);蛋氨酸的NOAEL和LOAEL为3.2和6.4g/d,精氨酸的NOAEL(30g/d);赖氨酸的NOAEL和LOAEL分别为6和7.5g/d,组氨酸的NOAEL和LOAEL分别为8和12g/d,分别为苯丙氨酸(12g/d)和NOAEL,丝氨酸(12g/d),鸟氨酸(12g/d)和瓜氨酸(24g/d)。这些第一组人类UL数据希望帮助国家和国际机构制定补充氨基酸的安全标准。
Individual amino acids are widely popular as supplements because of various perceived and real health benefits. However, currently, there are no recommendations set by national health agencies for tolerable upper intake levels (UL) for amino acids because of a lack of well-conducted human dose-response trials. In the past decade, under the initiative of the International Council on Amino Acid Science, a nonprofit organization, a series of UL human clinical studies were conducted. The goal of this narrative review is to summarize the studies on 6 essential amino acids (leucine, tryptophan, methionine, lysine, histidine, and phenylalanine), 2 nonessential amino acids (arginine and serine), and 2 nonproteinogenic amino acids (ornithine and citrulline) and provide the first set of ULs. A brief background of the concept of the DRI framework of UL, the concept of UL for amino acids, and a perspective of the results are also provided. The data suggest that in relatively healthy adult individuals, the tested amino acids are well tolerated, and ULs, or the no-observed-adverse-effect-level (NOAEL), lowest-observed-adverse-effect-level (LOAEL), can be determined. The ULs were for leucine-young (35 g/d), tryptophan (4.5 g/d), and leucine-elderly (30 g/d); NOAEL and LOAEL for methionine at 3.2 and 6.4 g/d, respectively; NOAEL for arginine (30 g/d); NOAEL and LOAEL for lysine at 6 and 7.5 g/d, respectively; NOAEL and LOAEL for histidine at 8 and 12 g/d, respectively; and NOAEL for phenylalanine (12 g/d), serine (12 g/d), ornithine (12 g/d) and citrulline (24 g/d). This first set of human UL data are hoped to help national and international agencies set safety standards for supplemental amino acids.