Sign Up for a Free Account

This is an image preview.
Start a Free Account
to view the full image.

  • Nearly 3,000 illustrations, including video clips of neurologic disorders.

  • Every article is reviewed by our esteemed Editorial Board for accuracy and currency.

  • Full spectrum of neurology in 1,200 comprehensive articles.

  • Listen to MedLink on the go with Audio versions of each article.

Abstract of the metabolic processes and uptake mechanisms of vitamin B12 in humans

The arrows in the "metabolism" part of the figure indicate an increase (if pointing upwards) or a decrease (if pointing downwards) in the metabolite or vitamin B12.

Abbreviations: HC, haptocorrin (probably more commonly known as R-protein or transcobalamin I); HCy, homocysteine; MMA, methylmalonic acid; TC, transcobalamin; TC-R, the transcobalamin receptor, CD320; VitB12, vitamin B12.

(Source: Mathew AR, Di Matteo G, La Rosa P, et al. Vitamin B12 deficiency and the nervous system: beyond metabolic decompensation-comparing biological models and gaining new insights into molecular and cellular mechanisms. Int J Mol Sci 2024;25[1]:590. Creative Commons Attribution 4.0 International [CC BY 4.0] license, creativecommons.org/licenses/by/4.0. Note this figure was modified by Dr. Douglas J Lanska from the original, which was intended to compare divergent metabolic processes and uptake mechanisms of vitamin B12 across human, mouse, and zebrafish.)

Related Article

Associated Disorders

  • Alcohol-tobacco amblyopia
  • Cerebral vascular disease
  • Dementia
  • Depression
  • Developmental delay
  • Folate deficiency
  • Gastric resection
  • Glossitis
  • Imerslund-Grasbeck syndrome
  • Malabsorption
  • Megaloblastic anemia
  • Myelopathy
  • Optic neuropathy
  • Pernicious anemia
  • Polyneuropathy
  • Regional enteritis
  • Subacute combined degeneration of the spinal cord