Vitamin-D-dependent rickets type II. Resistance of target organs to 1,25-dihydroxyvitamin D.
Studies were done to determine the cause for hypocalcemia, secondary hyperparathyroidism, osteomalacia and osteitis fibrosa cystica in a 22-year-old black woman. The patient had normal serum 25-hydroxyvitamin D (14 ng per milliliter) and markedly elevated serum 1,25-dihydroxyvitamin D (137 pg per milliliter). Vitamin D3, 4000 units per day for four weeks, increased the serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D to as high as 29 and 297 pg per milliliter, respectively, and corrected the hypocalcemia and secondary hyperparathyroidism. The results suggest that the disorder results from impaired end-organ response to 1,25-dihydroxyvitamin D. We propose that the entity be called vitamin-D-dependent rickets Type II.
D000328:Adult; D004100:Dihydroxycholecalciferols / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood / Q000378:metabolism*; D006962:Hyperparathyroidism, Secondary / Q000209:etiology; D006996:Hypocalcemia / Q000209:etiology; D007015:Hypophosphatemia, Familial / Q000097:blood / Q000145:classification / Q000378:metabolism*; D010018:Osteomalacia / Q000209:etiology; D014807:Vitamin D / Q000378:metabolism
D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D014807:Vitamin D