LINEAR GROWTH IN PATIENTS WITH HYPOPHOSPHATEMIC VITAMIN-D RESISTANT RICKETS - INFLUENCE OF TREATMENT REGIMEN AND PARENTAL HEIGHT

The effects of different treatment regimens and the influence of parental height on the statural growth of 40 patients with hereditary vitamin D-resistant hypophosphatemic rickets were investigated. Three treatment regimens, each with oral phosphate, were used: vitamin D (0.5 to 2 mg/day), calcidiol (50 to 200 μg/day), and 1α-hydroxyvitamin D3 (1 to 3 μg/day). Mean duration of follow-up was 9.5±5.1 years. The results show that (1) there was no acceleration of growth before puberty for the majority of children treated with vitamin D (12/16) or calcidiol (13/15), whereas 1α-hydroxyvitamin D3 promoted catch-up growth in 10 of 16 patients; (2) height gain during puberty was normal, irrespective of the treatment; (3) most vitamin D-treated male and female subjects and calcidiol-treated male subjects had short adult stature, but the majority (75%) of the 1α-hydroxyvitamin D3-treated groups had normal stature; (4) parental stature had little influence on the adult height of male subjects, but that of affected girls was positively correlated (p<0.002) with mid-parental height. These results demonstrate that 1α-hydroxyvitamin D3 is superior to vitamin D or calcidiol for improvement of stature of patients with hypophosphatemic vitamin D-resistant rickets, and indicate the importance of parental height in determining the adult height of affected girls. © 1990 The C.V. Mosby Company.