Lamarche Jorge, Nair Reji, Peguero Alfredo, Courville Craig
Department of Nephrology and Hypertension, James A. Haley Veterans Hospital and the University of South Florida, Tampa, FL 33612, USA.
Int J Nephrol. 2011;2011:146927. doi: 10.4061/2011/146927. Epub 2011 Mar 16.
Although a multitude of syndromes have been thoroughly described as a result of vitamin deficiencies, over consumption of such substances may also be quite dangerous. Intratubular crystallization of calcium oxalate as a result of hyperoxaluria can cause acute renal failure. This type of renal failure is known as oxalate nephropathy. Hyperoxaluria occurs as a result of inherited enzymatic deficiencies known as primary hyperoxaluria or from exogenous sources known as secondary hyperoxaluria. Extensive literature has reported and explained the mechanism of increased absorption of oxalate in malabsorptive syndromes leading to renal injury. However, other causes of secondary hyperoxaluria may also take place either via direct dietary consumption of oxalate rich products or via other substances which may metabolize into oxalate within the body. Vitamin C is metabolized to oxalate. Oral or parenteral administration of this vitamin has been used in multiple settings such as an alternative treatment of malignancy or as an immune booster. This article presents a clinical case in which ingestion of high amounts of vitamin C lead to oxalate nephropathy. This article further reviews other previously published cases in order to illustrate and highlight the potential renal harm this vitamin poses if consumed in excessive amounts.
尽管因维生素缺乏已详尽描述了众多综合征，但过量摄入此类物质也可能相当危险。高草酸尿症导致的草酸钙肾小管内结晶可引发急性肾衰竭。这种肾衰竭类型被称为草酸肾病。高草酸尿症可由遗传性酶缺乏即原发性高草酸尿症引起，也可由外源性来源即继发性高草酸尿症导致。大量文献报道并解释了吸收不良综合征中草酸盐吸收增加导致肾损伤的机制。然而，继发性高草酸尿症的其他原因也可能通过直接饮食摄入富含草酸盐的产品或通过体内可能代谢为草酸盐的其他物质发生。维生素C可代谢为草酸盐。这种维生素的口服或肠外给药已在多种情况下使用，如作为恶性肿瘤的替代治疗或作为免疫增强剂。本文介绍了一例因摄入大量维生素C导致草酸肾病的临床病例。本文进一步回顾了其他先前发表的病例，以说明并强调过量摄入这种维生素对肾脏可能造成的危害。
