Affiliation:
1. Katedra i Zakład Chemii i Analizy Leków, Wydział Nauk Farmaceutycznych w Sosnowcu, Śląski Uniwersytet Medyczny w Katowicach
Abstract
Cobalamin (vitamin B12) is a complex compound, which is classified as a water-soluble
vitamin. Absorption of cobalamin in the gut and its transport to cells is a unique process,
in which many proteins are involved. The loss of function of these proteins causes serious
cell homeostasis disturbance, which may result in the dysfunction of many tissues and
organs. Vitamin B12, a cofactor of methionine synthase, provides methylation process and
nucleic acid synthesis. Cobalamin is also necessary for methylmalonyl-CoA mutase activity.
The enzyme synthesizes succinyl-CoA, an intermediate in tricarboxylic acid cycle.
Vitamin B12 deficiency is an important and current health problem. It may be caused by
insufficient dietary intake, age, or disease-related malabsorption and genetic defects of
mechanisms involved in the absorption, transport and metabolism of cobalamin. Hypocobalaminemia can also result from long-term pharmacotherapy with medicines:
metformin, proton pump inhibitors (e.g. omeprazole) and H2-receptor antagonists
(e.g. ranitidine).
Significant clinical symptoms of cobalamin deficiency include hematological abnormalities,
mainly megaloblastic anemia, as well as neurological disorders resulting from degeneration
within the nervous system. Early diagnosis and starting treatment with vitamin B12 increase
chances for a complete cure. Therefore, the diagnostically important symptom of hypocobalaminemia
may be skin manifestations, mainly hyperpigmentations, but also premature
graying of hair.
The aim of this review article was to summarize the current state of knowledge on the
biological function of cobalamin, as well as the causes and consequences of its deficiency
at the molecular, cellular, tissue and organism level.
Subject
Infectious Diseases,Microbiology (medical)
Reference66 articles.
1. Agarwal A., Saini A.G., Attri S.: Reversible hyperpigmentationand paraparesis: A simple remedy! J. Pediatr., 2018; 201:294
2. Agrawala R.K., Sahoo S.K., Choudhury A.K., Mohanty B.K.,Baliarsinha A.K.: Pigmentation in vitamin B12 deficiency masqueradingAddison’s pigmentation: A rare presentation.Indian. J. Endocrinol. Metab., 2013; 17: S254–S256
3. Albrecht K., Siwicka A., Matysiak M., Dembiński Ł.: Genetycznieuwarunkowana postać niedokrwistości Addisona-Biermera– opis przypadku dwuletniej dziewczynki. Post. N. Med.,2016; 29: 36–41
4. Allen L.H.: How common is vitamin B-12 deficiency? Am. J.Clin. Nutr., 2009; 89: 693S–696S
5. Arora K., Sequeira J.M., Alarcon J.M., Wasek B., Arning E.,Bottiglieri T., Quadros E.V.: Neuropathology of vitamin B12deficiency in the CD320-/- mouse. FASEB J., 2019; 33: 2563–2573