Intestinal calcium absorption in exogenous hypercortisonism. Role of 25-hydroxyvitamin D and corticosteroid dose.
J Clin Invest
; 60(1): 253-9, 1977 Jul.
Article
em En
| MEDLINE
| ID: mdl-874087
ABSTRACT
Pharmacologic doses of corticosteroids impair intestinal calcium absorption and contribute to negative calcium balance. However, the relationship between the impaired calcium absorption and a possible defect in the conversion of vitamin D to its physiologically active form, 1,25-dihydroxyvitamin D, is unknown. We compared fractional calcium absorption (double-isotope method, 100-mg carrier) and serum 25-hydroxyvitamin D (25-OH-D) (Haddad method) in 27 patients receiving pharmacologic doses of prednisone with 27 age-, sex-, and season-matched normal subjects. In patients receiving high daily doses of prednisone (15-100 mg/day), calcium absorption (P < 0.02) and serum 25-OH-D (P < 0.001) were decreased. However, in patients receiving low doses (8-10 mg/day) or high doses (30-100 mg) of prednisone on an alternate-day schedule, both of these parameters were normal. Calcium absorption in the patients treated with daily prednisone correlated inversely with the dose of corticosteroids (r = -0.52, P < 0.025) and, in all steroid-treated patients, correlated directly with serum 25-OH-D (r = 0.58, P < 0.01). In four patients who received high-dose corticosteroid therapy for an average of 4 wk, serum 25-OH-D decreased by 35.5% from pretreatment values. Administration of a physiologic or near-physiologic dose of synthetic 1,25-dihydroxyvitamin D(3) (0.4 mug daily for 7 days) to patients receiving high-dose corticosteroids led to an increase in calcium absorption in all patients. These results suggest that calcium malabsorption in the corticosteroid-treated patients is due to a dose-related abnormality of vitamin D metabolism and not to a direct effect of corticosteroids on depressing transmucosal intestinal absorption of calcium.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prednisona
/
Cálcio
/
Hiperfunção Adrenocortical
/
Di-Hidroxicolecalciferóis
/
Hidroxicolecalciferóis
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
J Clin Invest
Ano de publicação:
1977
Tipo de documento:
Article