Normal calcitonin stimulation of serum calcitriol in patients with X-linked hypophosphatemic rickets.

Journal Article (Journal Article)

Patients with X-linked hypophosphatemic rickets (XLH) have normal or low calcitriol concentrations despite manifesting hypophosphatemia, a known stimulus of 25-hydroxyvitamin D-1 alpha-hydroxylase activity. In accord, administration of pharmacological doses of PTH results in a markedly blunted stimulation of calcitriol levels. In the murine homolog of the human disorder, the Hyp mouse, regulation of 25-hydroxyvitamin D-1 alpha-hydroxylase activity is defective in response to hypophosphatemia and PTH administration, but not in response to calcitonin administration. In the current study we administered calcitonin to controls and patients with XLH to test the hypothesis that calcitonin-stimulatable 25-hydroxyvitamin D-1 alpha-hydroxylase activity is normal in patients with XLH. We found that calcitriol concentrations increased in both groups to a similar degree (78.5 +/- 20.9 pmol/L in patients and 49.9 +/- 19.7 pmol/L in controls) and with a similar time course. Our results indicate that the complex and incomplete defect in the regulation of 25-hydroxyvitamin D-1 alpha-hydroxylase observed in Hyp mice also exists in humans.

Full Text

Duke Authors

Cited Authors

  • Econs, MJ; Lobaugh, B; Drezner, MK

Published Date

  • August 1992

Published In

Volume / Issue

  • 75 / 2

Start / End Page

  • 408 - 411

PubMed ID

  • 1639943

International Standard Serial Number (ISSN)

  • 0021-972X

Digital Object Identifier (DOI)

  • 10.1210/jcem.75.2.1639943


  • eng

Conference Location

  • United States