Harrington Dominic J, Stevenson Emma, Sobczyńska-Malefora Agata
The Nutristasis Unit, Synnovis, St Thomas' Hospital, London, UK.
School of Biosciences and Medicine, University of Surrey, Guildford, UK.
Ann Clin Biochem. 2025 Jan;62(1):22-33. doi: 10.1177/00045632241292432. Epub 2024 Oct 27.
Vitamin B (cobalamin; B) is an essential micronutrient, but deficiency is common. The prompt diagnosis and treatment of B deficiency protects against megaloblastic anaemia, neuropathy and neuropsychiatric changes. Biomarkers of B status include the measurement of serum B (also known as total B or serum cobalamin), holotranscobalamin (holoTC or 'active B12'), methylmalonic acid (MMA) and total plasma homocysteine (Hcy). There is no 'gold standard' test for deficiency and the sensitivity and specificity of each biomarker for the evaluation of B status is affected by analytical and biological factors that may confer a high degree of diagnostic uncertainty. Limited access to technical and clinical expertise can lead to an over-reliance on the serum B test, which is readily available and highly automated. In some cases, the sequential use of different B status biomarkers or the calculation of a composite B status score, derived from a panel of B biomarkers and adjusted for folate status and age, can be used to detect deficient states that may otherwise be overlooked when using a single biomarker approach. This review summarizes the utility of B-related biomarkers and describes approaches to their application and interpretation.
维生素B（钴胺素；B₁₂）是一种必需的微量营养素，但缺乏情况很常见。及时诊断和治疗维生素B缺乏可预防巨幼细胞贫血、神经病变和神经精神变化。维生素B状态的生物标志物包括血清维生素B（也称为总维生素B或血清钴胺素）、全转钴胺素（全转钴胺素或“活性维生素B₁₂”）、甲基丙二酸（MMA）和血浆总同型半胱氨酸（Hcy）的测量。目前尚无用于诊断缺乏的“金标准”检测方法，并且每种生物标志物评估维生素B状态的敏感性和特异性会受到分析和生物学因素的影响，这些因素可能导致高度的诊断不确定性。技术和临床专业知识获取有限可能导致过度依赖血清维生素B检测，该检测易于获得且高度自动化。在某些情况下，依次使用不同的维生素B状态生物标志物或计算综合维生素B状态评分（该评分源自一组维生素B生物标志物，并根据叶酸状态和年龄进行调整），可用于检测使用单一生物标志物方法时可能被忽视的缺乏状态。本综述总结了与维生素B相关的生物标志物的效用，并描述了其应用和解读方法。
