Vitamin D absorption in healthy subjects and in patients with intestinal malabsorption syndromes

Am J Clin Nutr. 1985 Oct;42(4):644-9. doi: 10.1093/ajcn/42.4.644.


We developed a test procedure for the clinical evaluation of the absorption of vitamin D. Serum vitamin D concentrations were evaluated in seven patients with intestinal fat malabsorption syndromes and in seven healthy, normal subjects, after being given a single oral dose of 50,000 IU (1.25 mg) vitamin D2. In the normal subjects, serum vitamin D concentrations rose from a baseline of less than 5 ng/ml to a peak of over 50 ng/ml by 12 h, gradually falling to baseline levels by 3 days. In five of the seven patients with intestinal fat malabsorption, oral administration of 50,000 IU vitamin D2 did not raise serum vitamin D concentrations above 10 ng/ml. Two patients with severe inflammatory bowel disease had a normal absorption pattern, however. These findings suggest that an oral vitamin D absorption test may be of value for determination of patients at risk for development of vitamin D deficiency. They also raise questions about the efficacy of oral vitamin D preparations in patients with intestinal fat malabsorption.

Publication types

  • Case Reports
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Capsules
  • Fats / metabolism
  • Female
  • Humans
  • Intestinal Absorption*
  • Malabsorption Syndromes / metabolism*
  • Male
  • Middle Aged
  • Vitamin D / administration & dosage
  • Vitamin D / blood
  • Vitamin D / metabolism*


  • Capsules
  • Fats
  • Vitamin D