Phosphorus
Phosphorus’s Functional Role
Phosphorus is present in our bodies as part of a chemical group called a phosphate group. These phosphate groups are essential as a structural component of cell membranes (as phospholipids), DNA and RNA, energy production (ATP), and regulation of acid-base homeostasis. Phosphorus however is mostly associated with calcium as a part of the mineral structure of bones and teeth. Blood phosphorus levels are not controlled as strictly as calcium so the PTH stimulates renal excretion of phosphate so that it does not accumulate to toxic levels.
Dietary Reference Intakes for Phosphorus
In comparison to calcium, most Americans are not at risk for having a phosphate deficiency. Phosphate is present in many foods popular in the American diet including meat, fish, dairy products, processed foods, and beverages. Phosphate is added to many foods because it acts as an emulsifying agent, prevents clumping, improves texture and taste, and extends shelf-life. The average intake of phosphorus in US adults ranges between 1,000 and 1,500 milligrams per day, well above the RDA of 700 milligrams per day. The UL set for phosphorous is 4,000 milligrams per day for adults and 3,000 milligrams per day for people over age seventy.
Table 10.3 Dietary Reference Intakes for Phosphorus
| Age Group | RDA (mg/day) | UL (mg/day) |
| Infants (0–6 months) | 100* | – |
| Infants (6–12 months) | 275* | – |
| Children (1–3 years) | 460 | 3,000 |
| Children (4–8 years) | 500 | 3,000 |
| Children (9–13 years) | 1,250 | 4,000 |
| Adolescents (14–18 years) | 1,250 | 4,000 |
| Adults (19–70 years) | 700 | 4,000 |
| Adults (> 70 years) | 700 | 3,000 |
| * denotes Adequate Intake |
Micronutrient Information Center: Phosphorus. Oregon State University, Linus Pauling Institute. http://lpi.oregonstate.edu/mic/minerals/phosphorus. Updated in July 2013. Accessed October 22, 2017.
Dietary Sources of Phosphorus
Table 10.4 Phosphorus Content of Various Foods
| Foods | Serving | Phosphorus (mg) | Percent Daily Value 1000 |
| Salmon | 3 oz. | 315 | 32 |
| Yogurt, nonfat | 8 oz. | 306 | 31 |
| Turkey, light meat | 3 oz. | 217 | 22 |
| Chicken, light meat | 3 oz. | 135 | 14 |
| Beef | 3 oz. | 179 | 18 |
| Lentils* | ½ c. | 178 | 18 |
| Almonds* | 1 oz. | 136 | 14 |
| Mozzarella | 1 oz. | 131 | 13 |
| Peanuts* | 1 oz. | 108 | 11 |
| Whole wheat bread | 1 slice | 68 | 7 |
| Egg | 1 large | 86 | 9 |
| Carbonated cola drink | 12 oz. | 41 | 4 |
| Bread, enriched | 1 slice | 25 | 3 |
Micronutrient Information Center: Phosphorus. Oregon State University, Linus Pauling Institute. http://lpi.oregonstate.edu/mic/minerals/phosphorus. Updated in July 2013. Accessed October 22, 2017.