Coburn J W, Hartenbower D L, Norman A W
West J Med. 1974 Jul;121(1):22-44.
Extensive experimental evidence has established a significant role of calciferol in the maintenance of normal calcium homeostasis. Present knowledge indicates that vitamin D(3) must first be converted to 25-OH-D(3) and then to 1,25(OH)(2)D(3), the most active known form of the steroid. Many of the factors regulating the rate of production of this last steroid from its precurser have been evaluated, and the concept that vitamin D functions as a steroid hormone seems to be well established. Deranged action of calciferol, caused by impaired metabolism of the steroid or through altered sensitivity of target tissues, may be involved in the pathophysiology of several disease states with abnormal calcium metabolism. It is noted that liver disease, osteomalacia due to anticonvulsant therapy, chronic renal failure, hypophosphatemic rickets, hypoparathyroidism, hyperparathyroidism, sarcoidosis and idiopathic hypercalciuria have possible relation to alterations in metabolism or action of vitamin D. The future clinical availability of 1,25(OH)(2)D(3) and other analogs of this steroid may offer potential therapeutic benefit in the treatment of certain of the disease entities discussed.
大量实验证据证实了钙化醇在维持正常钙稳态中的重要作用。目前的知识表明，维生素D(3)必须首先转化为25-OH-D(3)，然后再转化为1,25(OH)(2)D(3)，这是已知的该类固醇最具活性的形式。许多调节这种最终类固醇从其前体生成速率的因素已得到评估，维生素D作为类固醇激素发挥作用的概念似乎已得到充分确立。钙化醇的作用紊乱，由类固醇代谢受损或靶组织敏感性改变引起，可能参与了几种钙代谢异常疾病状态的病理生理学过程。值得注意的是，肝病、抗惊厥治疗引起的骨软化症、慢性肾功能衰竭、低磷血症性佝偻病、甲状旁腺功能减退症、甲状旁腺功能亢进症、结节病和特发性高钙尿症可能与维生素D代谢或作用的改变有关。1,25(OH)(2)D(3)和该类固醇的其他类似物未来在临床上的可用性可能为治疗某些所讨论的疾病实体提供潜在的治疗益处。
