Acromegaly and vitamin D metabolism: effect of bromocriptine treatment.

Fifteen acromegalic subjects were found to have elevated plasma levels of both 1,25(OH)2-vitamin D, 65 +/- 23 (SD) pg/ml [normal 33 + 15 pg/ml (SD)] and 24,25(OH)2-vitamin D, 6.8 +/- 1.6 (SD) ng/ml [normal 3.4 + 1.2 ng/ml (SD)]. Treatment with bromocriptine for 6 months reduced the plasma 1,25(OH)2-vitamin D3 level to 40 +/- 13 (SD) pg/ml, p less than 0.01 and the 24,25(OH)2-vitamin D level to 5.4 +/- 1.7 (SD) ng/ml, p less than 0.05.