Casella S J, Reiner B J, Chen T C, Holick M F, Harrison H E
Division of Pediatric Endocrinology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
J Pediatr. 1994 Jun;124(6):929-32. doi: 10.1016/s0022-3476(05)83184-1.
We examined two siblings who had severe rickets at ages 2 and 7 years, respectively, despite a history of adequate vitamin D intake. The patients' sera had calcium concentrations at the lower limits of normal, low phosphate concentrations, elevated alkaline phosphatase activity, and low levels of 25-hydroxyvitamin D. Treatment with high doses of vitamin D2 resulted in resolution of the biochemical abnormalities and radiographic deformities; pharmacologic doses of vitamin D2 were required to maintain normal concentrations of 25-hydroxyvitamin D in the serum even though vitamin D absorption was normal. These children may have a genetic defect of the 25-hydroxylation step in vitamin D activation.
我们检查了两名分别在2岁和7岁时患有严重佝偻病的兄弟姐妹，尽管他们有充足的维生素D摄入史。患者血清钙浓度处于正常下限，磷酸盐浓度低，碱性磷酸酶活性升高，且25-羟基维生素D水平低。高剂量维生素D2治疗使生化异常和影像学畸形得到缓解；即使维生素D吸收正常，仍需要药理剂量的维生素D2来维持血清中25-羟基维生素D的正常浓度。这些儿童可能在维生素D激活的25-羟化步骤存在基因缺陷。
