Raimann Jochen G, Levin Nathan W, Craig Ronald G, Sirover William, Kotanko Peter, Handelman Garry
Semin Dial. 2013 Jan-Feb;26(1):1-5. doi: 10.1111/sdi.12030. Epub 2012 Oct 29.
Vitamin C has several well-established roles in physiology including synthesis of collagen, carnitine and epinephrine, absorption of dietary iron, and mobilization of storage iron for erythropoeisis. Loss of several of these functions explains the pathology of scurvy, where defective collagen synthesis and anemia are major symptoms. Vitamin C deficiency is very common in dialysis patients and may arise from dialytic vitamin C clearance, restricted intake of vitamin C-rich foods, and increased vitamin C catabolism in vivo from inflammation. In the dialysis population, greater vitamin C intake may be needed for optimal health. Relationships between intake, body distribution, inflammation, and dialytic losses are complex and need further study. Concern about vitamin C metabolism leading to accumulation of tissue oxalate has led to the recommendation that vitamin C intake equals, but not exceeds, the intake recommended for the general population. Vitamin C deficiency in dialysis patients may have clinical consequences; a study in Renal Research Institute clinics found an association with periodontal disease. Data also support a role for vitamin C in prevention of dialysis-related anemia. New research questions are proposed in this editorial, with a discussion of strategies to determine the optimal provision of vitamin C for CKD patients.
维生素C在生理学中具有多种既定作用，包括胶原蛋白、肉碱和肾上腺素的合成，膳食铁的吸收，以及为红细胞生成动员储存铁。这些功能中的几种丧失解释了坏血病的病理，其中胶原蛋白合成缺陷和贫血是主要症状。维生素C缺乏在透析患者中非常常见，可能源于透析过程中维生素C的清除、富含维生素C食物的摄入受限，以及体内炎症导致的维生素C分解代谢增加。在透析人群中，可能需要摄入更多的维生素C以维持最佳健康状态。维生素C的摄入量、体内分布、炎症和透析损失之间的关系很复杂，需要进一步研究。由于担心维生素C代谢会导致组织草酸盐积累，因此建议维生素C的摄入量应等于但不超过一般人群的推荐摄入量。透析患者的维生素C缺乏可能会产生临床后果；肾研究所诊所的一项研究发现它与牙周病有关。数据也支持维生素C在预防透析相关贫血方面的作用。本社论提出了新的研究问题，并讨论了确定为慢性肾脏病患者最佳补充维生素C的策略。
