Department of Critical Care Medicine, Hospital de Clínicas, Dr Manuel Quintela, Faculty of Medicine, (University Hospital), Universidad de la República, UDELAR, Montevideo, Uruguay.
Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):662-8. doi: 10.1097/MCO.0b013e32833dfaec.
To analyse the anti-inflammatory and antioxidant properties of vitamin B12 and evaluate current evidence on vitamin B12 status in the critically ill with systemic inflammation.
Data on vitamin B12 status of intensive care unit patients are scarce. Cobalamins could potentially be useful agents for inhibiting nitric oxide synthase and nitric oxide production, controlling nuclear factor-kappa B activation, and restoring optimal bacteriostasis and phagocytosis in which transcobalamins play a proven role. The antioxidant properties of vitamin B12, with a glutathione-sparing effect, are secondary to stimulation of methionine synthase activity and reaction with free oxygen or nitrogen radicals. Large parenteral doses are routinely administered for cyanide poisoning, with only mild, reversible side-effects. Current evidence suggests that high-dose parenteral vitamin B12 may prove an innovative approach to treat critically ill systemic inflammatory response syndrome patients, especially those with severe sepsis/septic shock. In this setting, vitamin B12 and transcobalamins could modulate systemic inflammation contributing to the anti-inflammatory cascade and potentially improve outcome.
Despite evidence from animal studies, so far there are no clinical intervention trials that have studied vitamin B12 as a pharmaconutrient strategy for critical care. Well designed animal and clinical studies are required to clarify several outstanding questions on the optimal posology, safety, and efficacy of high-dose vitamin B12 in the critically ill.
分析维生素 B12 的抗炎和抗氧化特性，并评估目前关于全身炎症危重病患者维生素 B12 状态的证据。
关于重症监护病房患者维生素 B12 状态的数据稀缺。钴胺素可能是抑制一氧化氮合酶和一氧化氮产生、控制核因子-κB 激活以及恢复最佳抑菌和吞噬作用的有用药物，转钴胺素在其中发挥了已证实的作用。维生素 B12 的抗氧化特性具有谷胱甘肽节约作用，这是由于刺激蛋氨酸合成酶活性以及与游离氧或氮自由基反应所致。大剂量的维生素 B12 通常用于氰化物中毒的治疗，只有轻微、可逆的副作用。目前的证据表明，大剂量的维生素 B12 可能是治疗重症全身炎症反应综合征患者的一种创新方法，尤其是那些患有严重败血症/感染性休克的患者。在这种情况下，维生素 B12 和转钴胺素可以调节全身炎症，有助于抗炎级联反应，并可能改善预后。
尽管有动物研究的证据，但迄今为止，还没有研究维生素 B12 作为一种药物营养素策略来治疗重症监护的临床干预试验。需要进行精心设计的动物和临床研究，以阐明关于重症患者大剂量维生素 B12 的最佳剂量、安全性和疗效的几个悬而未决的问题。
