Rickets: It is Not Always Nutritional. A Rare Case of Vitamin D-Dependent Rickets (VDDR) Type I

Abstract

Rickets is typically due to nutritional cause, namely vitamin D and calcium deficiency worldwide. When there is suboptimal response to conventional vitamin D and calcium supplementation, alternative causes have to be sought. We report a rare case of vitamin D-dependent rickets (VDDR) who presented with rachitic features but normal total 25-hydroxyvitamin D 25(OH)D level. Conventional inactive vitamin D supplementation was ineffective and high dose of alfacalcidol was required to maintain normocalcaemia.