Rickets and alopecia with resistance to 1,25-dihydroxyvitamin D: two different clinical courses with two different cellular defects.

Unlabelled: Two unrelated patients, aged 22 months and 31 months, with alopecia and rickets resistant to 1,25-dihydroxyvitamin D (1,25-(OH)2D] (vitamin D-dependency type II) presented with similar biochemical and radiologic features. They were treated with large doses of vitamin D3 derivatives [25-hydroxyvitamin D3 (25-(OH)D3), 1,25-(OH)2D3, and 1 alpha-hydroxyvitamin D3] for 28 months and 6 yr, respectively. In both patients, serum 1,25-(OH)2D levels remained high (approximately 10- to 100-fold normal) during the different therapeutic regimens.

[Effects of the main derivatives of vitmain D in 3 siblings with "pseudo-deficiency" rickets].

Three siblings, respectively 20, 16 and 12 years old, presented with hypocalcemic vitamin D resistant rickets (Prader's type). Their clinical history included several periods of spontaneous cessation of therapy, with severe relapses. Since 1973, treatment was strictly observed, allowing to test the therapeutic effects of 25 OH D3, 1-25 (OH) 2 D3 and 1-alpha (OH) D3.