Micronutrients in chronic kidney disease

Abstract

Chronic Kidney Disease (CKD) is a leading public health problem that has received increased research attention because of its significantly increased prevalence. These patients are at risk of malnutrition due to several factors, including chronic comorbidities, poor nutritional intake, and uremia. It is known that malnutrition increases morbidity and mortality, possibly due to specific micronutrient deficiencies. In patients treated with renal replacement therapy (RRT), unrecognized losses of nutrients in dialysate or urine, poor food intake, intestinal dysfunction, inflammation, and abnormal metabolism may also contribute to micronutrient deficiencies. Some micronutrients are negatively associated with CKD stages. On the other hand, some other micronutrients' plasma concentration increases, paralleling the rise in creatinine concentration. CKD is characterized by inflammation due to oxidative stress. Many micronutrients are components of metalloenzymes and participate in reactive oxygen metabolism, free radical scavenging, and hormone activities. Therefore, the micronutrient levels are significant in ensuring optimal management among CKD patients with or without RRT. Different types of RRT may not have a similar effect on micronutrient levels. It is unclear whether all alterations of micronutrient status contribute to the poor outcomes of CKD patients. Also, it is unclear whether routine micronutrient intake (vitamins and trace elements) affects outcomes in adults with CKD 1-5D, non-dialysis, and transplant. As a result, there are many controversial results in the literature, and more information about the micronutrient status of CKD patients receiving RRT is needed. Here, we aimed to review the relationships between micronutrient levels and clinical outcomes in CKD patients and the effects of different types of RRT on micronutrient levels.