Office of Dietary Supplements, National Institutes of Health, Bethesda, MD 20892-7517, USA.
Am J Clin Nutr. 2011 Jul;94(1):313S-321S. doi: 10.3945/ajcn.111.013243. Epub 2011 May 18.
A roundtable to discuss the measurement of vitamin B-12 (cobalamin) status biomarkers in NHANES took place in July 2010. NHANES stopped measuring vitamin B-12-related biomarkers after 2006. The roundtable reviewed 3 biomarkers of vitamin B-12 status used in past NHANES--serum vitamin B-12, methylmalonic acid (MMA), and total homocysteine (tHcy)--and discussed the potential utility of measuring holotranscobalamin (holoTC) for future NHANES. The roundtable focused on public health considerations and the quality of the measurement procedures and reference methods and materials that past NHANES used or that are available for future NHANES. Roundtable members supported reinstating vitamin B-12 status measures in NHANES. They noted evolving concerns and uncertainties regarding whether subclinical (mild, asymptomatic) vitamin B-12 deficiency is a public health concern. They identified the need for evidence from clinical trials to address causal relations between subclinical vitamin B-12 deficiency and adverse health outcomes as well as appropriate cutoffs for interpreting vitamin B-12-related biomarkers. They agreed that problems with sensitivity and specificity of individual biomarkers underscore the need for including at least one biomarker of circulating vitamin B-12 (serum vitamin B-12 or holoTC) and one functional biomarker (MMA or tHcy) in NHANES. The inclusion of both serum vitamin B-12 and plasma MMA, which have been associated with cognitive dysfunction and anemia in NHANES and in other population-based studies, was preferable to provide continuity with past NHANES. Reliable measurement procedures are available, and National Institute of Standards and Technology reference materials are available or in development for serum vitamin B-12 and MMA.
一个讨论 NHANES 中维生素 B-12（钴胺素）状态生物标志物测量的圆桌会议于 2010 年 7 月举行。NHANES 在 2006 年后停止测量维生素 B-12 相关生物标志物。该圆桌会议回顾了过去 NHANES 中使用的 3 种维生素 B-12 状态生物标志物——血清维生素 B-12、甲基丙二酸（MMA）和总同型半胱氨酸（tHcy）——并讨论了测量全钴胺素（holoTC）用于未来 NHANES 的潜在效用。圆桌会议重点关注公共卫生考虑因素以及过去 NHANES 使用的或未来 NHANES 可用的测量程序和参考方法和材料的质量。圆桌会议成员支持在 NHANES 中重新引入维生素 B-12 状态测量。他们注意到，关于亚临床（轻度、无症状）维生素 B-12 缺乏是否是一个公共卫生问题，存在不断演变的关注和不确定性。他们确定需要临床试验证据来解决亚临床维生素 B-12 缺乏与不良健康结果之间的因果关系，以及解释维生素 B-12 相关生物标志物的适当截止值。他们一致认为，单个生物标志物的敏感性和特异性问题突出表明，需要在 NHANES 中至少包括一种循环维生素 B-12（血清维生素 B-12 或 holoTC）和一种功能性生物标志物（MMA 或 tHcy）。纳入血清维生素 B-12 和血浆 MMA，它们与 NHANES 及其他基于人群的研究中的认知功能障碍和贫血相关，这更有利于与过去的 NHANES 保持连续性。可靠的测量程序是可用的，国家标准与技术研究所的参考材料可用于血清维生素 B-12 和 MMA 的测量，或正在开发中。
