title: Serum levels of 25-hydroxyvitamin D in postmenopausal osteoporosis.
abstract: Serum concentrations of 25-hydroxy-vitamin D were measured in a group of women with symptomatic postmenopausal osteoporosis, assessed by bone biopsy. A competitive protein binding assay was used, which included a chromatographic step. Accurate surveys of dietary or therapeutic vitamin D intake and light environment were obtained in each patient. Women with severe postmenopausal osteoporosis were found to have significantly (P less than 0.001) higher serum levels of 25-hydroxyvitamin D than age-matched normal women, the mean values being 27.5 ng/ml (+/- 13.6 SD) and 9.2 ng/ml (+/-5.7), respectively. The authors hypothesize that the reduction in 1,25-dihydroxyvitamin D, recently reported in postmenopausal osteoporotic women, might be responsible for the increased serum levels of 25-hydroxyvitamin D through an inadequate product inhibition of liver vitamin D 25-hydroxylase.
mesh_terms: D015652:25-Hydroxyvitamin D 2; D000328:Adult; D000368:Aged; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000652:urine; D004872:Ergocalciferols / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000652:urine; D012016:Reference Values
chemical_list: D004872:Ergocalciferols; D015652:25-Hydroxyvitamin D 2; D000242:Cyclic AMP; D002118:Calcium