Marks Brynn E, Doyle Daniel A
J Pediatr Endocrinol Metab. 2016 Feb;29(2):127-32. doi: 10.1515/jpem-2015-0133.
The widespread use of supplemental vitamin D has dramatically reduced the incidence of rickets. While generally considered a safe practice, there is potential for toxicity in patients with idiopathic infantile hypercalcemia (IIH). Inadequate 24-hydroxylase-enzyme activity renders these individuals unable to degrade active vitamin D, resulting in hypercalcemia due to increased intestinal calcium absorption, decreased renal calcium excretion, and increased osteoclastic bone activity. Clinicians should be aware that even therapeutic doses of vitamin D can prove harmful for patients with CYP24A1 mutations. Studies have also demonstrated a link between inadequate 24-hydroxylase activity and nephrocalcinosis, renal insufficiency, and calcium containing kidney stones, further emphasizing the importance of early recognition of this disease and judicious use of vitamin D. We present a case with an interesting diagnostic algorithm used to diagnose IIH when given an incomplete history and subsequently review the existing literature on the subject.
补充维生素D的广泛使用已显著降低了佝偻病的发病率。虽然一般认为这是一种安全的做法，但特发性婴儿高钙血症（IIH）患者存在中毒的可能性。24-羟化酶活性不足使这些个体无法降解活性维生素D，由于肠道钙吸收增加、肾钙排泄减少和破骨细胞骨活性增加而导致高钙血症。临床医生应意识到，即使是治疗剂量的维生素D对携带CYP24A1突变的患者也可能有害。研究还表明，24-羟化酶活性不足与肾钙质沉着症、肾功能不全和含钙肾结石之间存在联系，这进一步强调了早期识别这种疾病和谨慎使用维生素D的重要性。我们介绍了一个病例，该病例采用了一种有趣的诊断算法，用于在病史不完整的情况下诊断IIH，并随后回顾了关于该主题的现有文献。
