Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK.
Second Department of Neurology, School of Medicine, Attikon University Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece.
Nutrients. 2023 Jun 21;15(13):2823. doi: 10.3390/nu15132823.
Vitamin B6 is a water-soluble vitamin that is naturally present in many foods and is accessible in many dietary supplements. The three natural forms are pyridoxine, pyridoxal, and pyridoxamine. Both vitamin B6 deficiency and high B6 intake have been described as risk factors for developing peripheral neuropathy (PN). The aim of this systematic review is to characterize and comprehensively describe B6-related PN.
A systematic, computer-based search was conducted using the PubMed database. Twenty articles were included in this review.
Higher vitamin B6 levels, which usually occur following the taking of nutritional supplements, may lead to the development of a predominantly, if not exclusively, sensory neuropathy of the axonal type. After pyridoxine discontinuation, such patients subjectively report improved symptoms. However, although low vitamin B6 levels can be seen in patients suffering from peripheral neuropathy of various etiologies, there is no firm evidence that low B6 levels have a direct causal relationship with PN. Many studies suggest subjective improvement of neuropathy symptoms in patients suffering from PN of various etiologies after receiving B6 supplementation; however, no data about B6 administration as a monotherapy exist, only as part of a combination treatment, usually with other vitamins. Therefore, the potential therapeutic role of B6 cannot be confirmed to date. Supplementation with vitamin B6, even as part of a nutritional multivitamin supplement, has not been proven harmful at permitted daily doses in patients who already suffer from PN.
Current scientific evidence supports a neurotoxic role of B6 at high levels. Although some studies suggest that low B6 is also a potential risk factor, further studies in this area are needed.
维生素 B6 是一种水溶性维生素，天然存在于许多食物中，也可作为许多膳食补充剂的成分。三种天然形式为吡哆醇、吡哆醛和吡哆胺。维生素 B6 缺乏和摄入过高都被描述为周围神经病（PN）的风险因素。本系统综述旨在描述与 B6 相关的周围神经病的特征并进行全面描述。
使用 PubMed 数据库进行了系统的计算机检索。本综述共纳入了 20 篇文章。
通常在服用营养补充剂后，维生素 B6 水平升高可能导致以轴索性感觉神经病为主，如果不是完全为主的周围神经病。停止使用吡哆醇后，这些患者会主观地报告症状改善。然而，尽管在患有各种病因的周围神经病的患者中可以看到低维生素 B6 水平，但没有确凿的证据表明低 B6 水平与 PN 有直接因果关系。许多研究表明，患有各种病因的周围神经病的患者在接受 B6 补充后，神经病变症状会主观改善；然而，尚无 B6 作为单一疗法的给药数据，仅作为联合治疗的一部分，通常与其他维生素联合使用。因此，迄今为止，B6 的潜在治疗作用尚无法得到证实。在已经患有 PN 的患者中，即使以维生素 B6 作为营养复合维生素补充剂的一部分，在允许的每日剂量下补充维生素 B6 也不会造成伤害。
目前的科学证据支持高水平的 B6 具有神经毒性作用。尽管一些研究表明低 B6 也是一个潜在的危险因素，但该领域还需要进一步的研究。
