Notwithstanding the importance of nutritional deficiencies in the etiology and associated adverse outcomes of the protein energy wasting syndrome of chronic kidney disease (CKD),1 the knowledge of the burden and bioactivity of many nutrients and their effect on the health of the patients with CKD is very incomplete. This is relevant for defining desirable intake ranges of energy-producing nutrients, such as carbohydrates, proteins, and fats, as well as vitamins, minerals, and trace elements. Without sufficient data and understanding, the use of nutritional supplements to prevent inadequate intake may result in either excessive or insufficient intake of micronutrients for people with CKD, with consequences in many cases yet to be explored.