Vitamin D absorption in healthy subjects and in patients with intestinal malabsorption syndromes.
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.
D000328:Adult; D002214:Capsules; D005223:Fats / Q000378:metabolism; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008286:Malabsorption Syndromes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
D002214:Capsules; D005223:Fats; D014807:Vitamin D