title: Vitamin D-binding protein levels in female patients with primary hyperparathyroidism.
abstract: OBJECTIVE
  To determine whether low levels of vitamin D-binding protein (DBP) are related to 25-hydroxyvitamin D (25[OH]D) deficiency in female patients with primary hyperparathyroidism (PHPT).
  
  
  METHODS
  Twenty-five female patients with PHPT (serum calcium level >10.2 mg/dL and intact parathyroid hormone (iPTH) level >66 pg/mL) and 25 healthy age- and body mass index-matched female control subjects were xaminod. Serum calcium and iPTH levels were determined by commercial laboratories. Levels of 25(OH)D and 1,25-dihydroxyvitamin D (1,25[OH]₂D) were determined by radioimmunoassay, and DBP level was determined by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Serum iPTH and calcium levels were higher in PHPT patients than control subjects (P<.001). Levels of 25(OH)D, albumin, and DBP were lower in the serum of PHPT patients than control subjects (P<.01). There were no significant differences in 1,25(OH)₂D and free 25(OH)D levels between PHPT patients and control subjects. DBP level was inversely correlated with calcium (r = -0.47; P<.01) and iPTH (r = -0.31; P<.05) levels. The 25(OH)D level correlated positively with both DBP (r = 0.28; P<.05) and albumin (r = 0.44; P<.05) levels.
  
  
  CONCLUSIONS
  Both serum 25(OH)D and DBP levels were lower in female patients with PHPT compared with control subjects. We suggest that a low DBP level contributes to the low 25(OH)D level observed in female PHPT patients. The etiology of the decrease in DBP and its relationship to calcium, 25(OH)D, and PTH levels require further investigation.
authors: Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Robert Wood Johnson Medical School-RWJMS, New Brunswick, NJ 08903-0019, USA. xw030912@aol.com
authors: Xiangbing
authors: X
authors: Wang
authors: Sue A
authors: SA
authors: Shapses
authors: Sun
authors: S
authors: Wei
authors: Deeptha
authors: D
authors: Sukumar
authors: Jaya
authors: J
authors: Ghosh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood*; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014809:Vitamin D-Binding Protein / Q000097:blood*; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium