1,25-DIHYDROXYCHOLECALCIFEROL AND 1α-HYDROXYCHOLECALCIFEROL IN HYPOPARATHYROIDISM

Abstract

Small amounts (0·68-2·7 μg.) of 1,25- dihydroxycholecalciferol (1,25-D.H.C.C.), the hormonally active metabolite of vitamin D3, or its synthetic analogue 1α-hydroxycholecalciferol (1α-H.C.C.) rapidly corrected the low plasma-calcium and improved symptoms when given daily to two patients with hypoparathyroidism. The rise in plasma-calcium could be maintained for as long as treatment continued but was readily reversible. The efficacy of minute doses of 1,25-D.H.C.C. and 1α-H.C.C. may indicate that the production of biologically active metabolites of vitamin D is impaired in hypoparathyroidism, and could offer advantages in treatment.