Association of osteopetrosis and vitamin D-resistant rickets.

The following report concerns a case of malignant osteopetrosis associated with hypocalcemic rickets unresponsive to vitamin D. Parathyroid hormone (PTH) and Calcitonin (CT) secretions were studied in basal conditions and under calcium gluconate infusion, before and after high doses of vitamin D. Basal values (PTH: 690 pg Eq/ml; CT: 560 pg/ml) were found to be much higher than in five control subjects of the same age group, even after vitamin D therapy (PTH: 990 pg Eq/ml; CT:450 pg/ml). Like rickets, PTH and CT secretions do not seem, therefore, to be notably influenced by vitamin D therapy.