Hypercalcemia in active pulmonary tuberculosis.

We describe four cases of active pulmonary tuberculosis with hypercalcemia. The hypercalcemia developed three to eight weeks after the patients were admitted to the hospital, when clinical improvement due to specific drug therapy for the infection was also evident. The abnormality persisted for three to seven weeks and subsided spontaneously. In each case, the serum level of 1,25-dihydroxyvitamin D determined during the period of hypercalcemia (at the peak in three of the four cases) was low. This suggests that altered vitamin D metabolism is not the basis for hypercalcemia in all cases of pulmonary tuberculosis.