The role of calcitonin and parathyroid hormone in the pathogenesis of post-thyroidectomy hypocalcemia.

Permanent hypocalcemia complicating thyroidectomy is a rare complication, whereas transient post-thyroidectomy hypocalcemia occurs frequently. Ten patients were studied in an attempt to elucidate the underlying mechanisms. An early and transient postoperative rise in calcitonin (CT) corresponding to a decline in calcium levels was demonstrated. Though there was no significant depression of parathyroid hormone (PTH) levels, the failure of the parathyroids to respond to hypocalcemic stimuli suggests a degree of at least transient parathyroid insufficiency. Transiently elevated CT levels appear to play a significant role in the commonly observed early, transient post-thyroidectomy hypocalcemia following subtotal and total thyroidectomy.