What is the dietary phosphorus intake
Organic phosphorus is found in meat, fish, dairy, whole grains, and nuts. However, most of the phosphorus we encounter in our diet is in the form of inorganic phosphorus added during food processing to enhance flavor and to improve color, and it serves as a preservative. Between 40% and 80% of dietary phosphorus is absorbed. The variability is largely due to the type of phosphorus consumed. Organic phosphorus is typically bound to proteins and must be metabolized to phosphate prior to absorption. Only about 40% to 60% of organic phosphorus is absorbed. Phosphate from animal protein is better absorbed than plant phosphate (phytate). Inorganic phosphate is more bioavailable, with as high as 90% absorption. The institute of medicine recommends 750 mg of phosphorus per day, with larger requirements (1250 mg/day) for children and pregnant women.
Food tables that list the phosphorus content do not include the phosphorus used as preservatives and so tend to underestimate daily phosphorus intake by as much as 272 to 350 mg.
Phosphate absorption in the gastrointestinal (GI) tract is largely unregulated, so increased dietary phosphate ingestion increases phosphate absorption. Active (1,25-OH) vitamin D also increases phosphate absorption.
