Sign Up for a Free Account

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

Sign Up for a Free Account For information on discounts, see Plans & Pricing

  • 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.

Alterations in biochemical pathways induced by nitrous oxide

Nitrous oxide inactivates vitamin B12 by oxidation of the cobalt atom, leading to functional defects in vitamin B12 as a cofactor for the catabolism of homocysteine and methylmalonic acid. Thus, the circulating concentrations of methylmalonic acid and homocysteine are increased in N2O-induced vitamin B12 deficiency.

Abbreviations: AdB12, adenosyl-vitamin B12; CBS, cystathionine beta-synthase; MeB12, methyl-vitamin B12; MMCoAM, methylmalonyl- CoA mutase; MTR, methionine synthase; N2O, nitrous oxide; THF, 5-methyl tetrahydrofolate.

(Source: Leleu D, Denimal D. A case of functional vitamin B12 deficiency after recreational nitrous oxide use. Biochem Med [Zagreb] 2024;34[1]:010801. Creative Commons Attribution 4.0 International [CC BY 4.0] license, creativecommons.org/licenses/by/4.0.)

Related Article

Related Media

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