Biological effects of inorganic phosphate: potential signal of toxicity

• Published in: Journal of toxicological sciences Vol. 40; no. 1; pp. 55 - 69
• Main Authors: Hong, Seong-Ho, Park, Sung-Jin, Lee, Somin, Kim, Sanghwa, Cho, Myung-Haing
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Toxicology 01.02.2015
• Subjects: Animals; Biological Phenomena - drug effects; Carcinogenesis - drug effects; Cardiovascular System - drug effects; Food Additives; Humans; Inorganic phosphate toxicity; Kidney - drug effects; Mice; Organ toxicity; Phosphate Transport Proteins - physiology; Phosphates - adverse effects; Phosphates - metabolism; Phosphates - physiology; Phosphates - toxicity; Recommended Dietary Allowances; Signal Transduction - drug effects; Sodium - physiology; Sodium-dependent phosphate co-transporters; Tumorigenesis
• ISSN: 0388-1350; 1880-3989
• DOI: 10.2131/jts.40.55

Inorganic phosphate (Pi) plays crucial roles in several biological processes and signaling pathways. Pi uptake is regulated by sodium-dependent phosphate (Na/Pi) transporters (NPTs). Moreover, Pi is used as a food additive in food items such as sausages, crackers, dairy products, and beverages. However, the high serum concentration of phosphate (> 5.5 mg/dL) can cause adverse renal effects, cardiovascular effects including vascular or valvular calcification, and stimulate bone resorption. In addition, Pi can also alter vital cellular signaling, related to cell growth and cap-dependent protein translation. Moreover, intake of dietary Pi, whether high (1.0%) or low (0.1%), affects organs in developing mice, and is related to tumorigenesis in mice. The recommended dietary allowance (RDA) of Pi is the daily dietary intake required to maintain levels above the lower limit of the range of normal serum Pi concentration (2.7 mg/dL) for most individuals (97-98%). Thus, adequate intake of Pi (RDA; 700 mg/day) and maintenance of normal Pi concentration (2.7-4.5 mg/dL) are important for health and prevention of diseases caused by inadequate Pi intake.