Lis Kinga
Department of Allergology, Clinical Immunology and Internal Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, ul. Ujejskiego 75, 85-168 Bydgoszcz, Poland.
Biomedicines. 2025 Mar 26;13(4):801. doi: 10.3390/biomedicines13040801.
Vitamin B12 is the common name for a group of cobalamins, which are cobalt corrines. Cobalamins are water-soluble B vitamins. Vitamin B12, as a coenzyme of various enzymes, is an essential component of many key metabolic processes in the body. Vitamin B12 deficiency causes dysfunction of various organs and systems in the body, including the central nervous system. Humans, like other animals, are unable to synthesize cobalamin. This vitamin must be supplied with a balanced diet. The only valuable dietary sources of cobalamin are foods of animal origin, especially offal (e.g., liver). Vegan and vegetarian diets are deficient in vitamin B12. People who follow this nutritional model require systematic cobalamin supplementation, usually in oral form. Other causes of cobalamin deficiency are various pathogenetic processes, in the course of which any of the stages of the complicated process of absorption of this vitamin from the gastrointestinal tract are impaired. Disorders of intestinal absorption of vitamin B12 require systematic supplementation of cobalamin parenterally (usually by intramuscular or subcutaneous injections) for the rest of life. Supplementary therapy with vitamin B12 may cause various adverse reactions, among which hypersensitivity reactions of various spectrums and intensity of symptoms are possible. According to available data, hypersensitivity to cobalamin is more likely after intramuscular or subcutaneous administration than in oral form. It also seems that long-term administration of cobalamin predisposes to allergy to vitamin B12, regardless of its chemical form. Although hypersensitivity to cobalamin is rather rare, it can also be of great clinical importance. This is due to the fact that vitamin B12 deficiency affects a significant part of the population, especially the elderly and those with chronic diseases that impair its absorption. In addition, supplementary therapy with cobalamin is long-term (usually lifelong) and there is no alternative form of treatment. For these reasons, solutions are sought that will allow for the safe continuation of treatment supplementing cobalamin deficiency. Various cyanocobalamin desensitization protocols are proposed, differing in duration, the dynamics of gradual dose increase, or the method of injection (intramuscular or subcutaneous). An analysis of available data in this field suggests that desensitization with cyanocobalamin seems to be an effective way to obtain tolerance to vitamin B12, allowing for long-term supplementation of this vitamin regardless of the chemical form, dose size, frequency, or route of administration.
维生素B12是一组钴胺素的通用名称，钴胺素是含钴的咕啉类化合物。钴胺素是水溶性B族维生素。维生素B12作为多种酶的辅酶，是人体许多关键代谢过程的重要组成部分。维生素B12缺乏会导致人体各器官和系统功能障碍，包括中枢神经系统。与其他动物一样，人类无法合成钴胺素。这种维生素必须通过均衡饮食来提供。钴胺素唯一有价值的膳食来源是动物源性食物，尤其是内脏（如肝脏）。纯素和素食饮食中缺乏维生素B12。遵循这种营养模式的人需要系统地补充钴胺素，通常采用口服形式。钴胺素缺乏的其他原因是各种致病过程，在此过程中，维生素从胃肠道吸收的复杂过程的任何阶段都会受损。维生素B12肠道吸收障碍需要在余生中通过肠外途径（通常通过肌肉注射或皮下注射）系统地补充钴胺素。维生素B12补充治疗可能会引起各种不良反应，其中可能出现各种症状谱和强度的过敏反应。根据现有数据，肌肉注射或皮下注射后对钴胺素过敏的可能性比口服形式更大。似乎长期使用钴胺素也会使人更容易对维生素B12过敏，无论其化学形式如何。尽管对钴胺素过敏相当罕见，但它也可能具有重要的临床意义。这是因为维生素B12缺乏影响了相当一部分人群，尤其是老年人和患有损害其吸收的慢性疾病的人。此外，钴胺素补充治疗是长期的（通常是终身的），并且没有替代治疗形式。由于这些原因，人们正在寻找能够安全继续治疗钴胺素缺乏症的解决方案。提出了各种不同的氰钴胺脱敏方案，在持续时间、逐渐增加剂量的动态过程或注射方法（肌肉注射或皮下注射）方面存在差异。对该领域现有数据的分析表明，氰钴胺脱敏似乎是获得对维生素B12耐受性的有效方法，无论其化学形式、剂量大小、频率或给药途径如何，都能长期补充这种维生素。
