Hypercalcaemia induced by increased thyroxine substitution in a patient treated with dihydrotachysterol.

The metabolism of vitamin D is essential in the control of bone and mineral metabolism. Hyperthyroidism as well as hypothyroidism effect the metabolism of bone tissue and vitamin D. We present a dihydrotachysterol-calcium treated patient with post-operative hypothyroidism, who developed hypercalcaemia, when the thyroxine dosage was increased.