Plasma 25-hydroxyvitamin D and alkaline phosphatase isoenzymes in hyperthyroidism.

Plasma 25-hydroxyvitamin D (25-OHD) values in 22 hyperthyroid patients did not differ significantly from those of controls matched for age, sex, and the time of year that plasma samples were taken. In the hyperthyroid group, plasma alkaline phosphatase was significantly higher than in controls, and an increase in bone type alkaline phosphatase occurred in 50%. In the 18 female hyperthyroid patients the plasma gamma-glutamyl transferase was significantly increased compared with controls. Mean values for plasma albumin, alanine transferase, and calcium showed no significant difference between hyperthyroid and control patients.