Premature Cranial Synostosis in X‐Linked Hypophosphatemic Rickets: Possible Precipitation by 1‐alpha‐OH‐Cholecalciferol Intoxication

Abstract
A child suffering from X-linked hypophosphatemic rickets developed vitamin D intoxication under treatment with 1-alpha-OH-cholecalciferol (1(OH)D3) and phosphorus. Beside the usual findings in this condition he showed precocious synostosis of the skull with signs of raised intracranial pressure. In view of earlier reports of coincidence of craniostenosis and X-linked hypophosphatemic rickets, we conclude that the possibility exists that intoxication with 1(OH)D3 has been the precipitating factor. In addition we found hypersensitivity to 1(OH)D3 2 months after cessation of treatment, and normal levels of calcitriol (1,25(OH)2D3) at the same time.