Vitamin D-Dependent Rickets Type I And Type II
August 1997
in “
Pediatrics International
”
TLDR VDDR I and II are genetic disorders affecting vitamin D use, causing rickets, with VDDR I treatable by vitamin D supplements and VDDR II needing high doses and calcium.
Vitamin D-dependent rickets type I (VDDR I) and type II (VDDR II) were identified as hereditary defects in vitamin D metabolism. VDDR I was associated with a deficiency in renal 25-hydroxyvitamin D-1α-hydroxylase, leading to muscle weakness and rickets, which could be managed with normal doses of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3. VDDR II involved defects in the intracellular vitamin D receptor (VDR), characterized by severe rickets and alopecia due to mutations in the VDR gene. Treatment for VDDR II required large doses of vitamin D analogs and calcium, though the response varied.
