title: The value of serum 25-hydroxyvitamin D measurements in hypoparathyroid and pseudohypoparathyroid patients treated with calciferol.
abstract: In 23 patients with hypoparathyroidism or pseudohypoparathyroidism treated with vitamin D, and in whom the dosage was adjusted downward or upward in response to hypercalcemia or hypocalcemia respectively, assays of serum 25-hydroxyvitamin D (25-OHD) were carried out in addition to the usual serum calcium assays. In 120 assays there was a significant correlation between serum 25-OHD levels and serum calcium levels (corrected for serum albumin). There was, however, no clear distinction between the 25-OHD levels of patients who were hypocalcemic, normocalcemic or hypercalcemic. The highest serum 25-OHD level found in a hypocalcemic patient was 1193 nmol/L and the lowest serum 25-OHD level found in a hypercalcemic patient was 605 nmol/L. It was not possible to predict subsequent episodes of hypocalcemia or hypercalcemia from the serum 25-OHD levels. The 25-OHD assay was found to be useful only in checking compliance. We conclude that the assay of serum 25-OHD is of no more value than serum calcium alone in the management of compliant patients.
mesh_terms: D015652:25-Hydroxyvitamin D 2; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D004872:Ergocalciferols / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D011547:Pseudohypoparathyroidism / Q000097:blood* / Q000188:drug therapy
chemical_list: D004872:Ergocalciferols; D015652:25-Hydroxyvitamin D 2; D002118:Calcium