Effect of cimetidine on hepatic vitamin D metabolism in humans

Digestion. 1990;46(2):61-4. doi: 10.1159/000200333.


Cimetidine inhibits the action of vitamin D-hydroxylase (a hepatic mixed-function oxidase) in the rat. Therefore, the hypothesis was tested that this H2 receptor antagonist would affect vitamin D metabolism in humans. Nine adult patients were treated with 400 mg cimetidine orally twice daily during a period from winter to summer, when days were becoming longer. Serum levels of 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D and 1,25-dihydroxyvitamin D were monitored before treatment, after 4 weeks of treatment, and 1 month after cessation of treatment. No seasonal increase in the level of 25-hydroxyvitamin D was observed during the period of treatment, but the level rose significantly after withdrawal of the drug. The other hydroxylates of vitamin D were not affected. Levels of albumin, total calcium, phosphorus and alkaline phosphatase remained normal. The data suggest that short-term treatment with cimetidine could potentially perturb vitamin D metabolism in man.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cimetidine / therapeutic use*
  • Female
  • Humans
  • Hydroxycholecalciferols / blood
  • Liver / metabolism*
  • Male
  • Middle Aged
  • Peptic Ulcer / drug therapy
  • Seasons
  • Vitamin D / metabolism*


  • Hydroxycholecalciferols
  • Vitamin D
  • Cimetidine