Dietary intake of phosphorus (Pi) is an important determinant of Pi balance in patients who have chronic kidney disease (CKD) and a reduced GFR. High dietary Pi burden may promote vascular calcification and cardiovascular events. Recently, Ohnishi and Razzaque suggest that phosphate toxicity accelerates the mammalian aging process and that reducing the phosphate burden can delay the aging (FASEB J 24, 3562, 2010) . Dietary Pi is derived largely from foods with high protein content or food additives. Accurate information on the Pi content of foods is needed to achieve a low Pi intake and effectively manage CKD and the aging. In this review, we discuss the risk of dietary Pi intake in CKD and the aging.