The Recommended Dietary Allowance (RDA) for phosphorus for both adult men and adult women is 700 mg. However, in direct contrast to the tendency of most diets to be deficient in other nutrients such as calcium and magnesium, most Americans consume more phosphorus than they should. The average intake has been found to be as much as 1,300 mg., daily for men and 1,000 mg., daily for women.
On the other hand, people with the medical conditions listed in the deficiency section may need to increase their dietary intake of phosphorus above the recommended levels.
The Upper Tolerable Limit for dietary phosphorus has been set at 4,000 mg. per day. For those of age 70 and up, the Upper Tolerable Limit drops to 3,000 mg. per day due to the increased likelihood of renal disease associated with advanced age. Ingestion of higher quantities than the designated Upper Tolerable Limit at any age can have toxic effects.