This mineral is needed for maintaining strong bones and teeth; extracting energy from food; and forming enzymes, cell membranes, and genetic material. It also helps the body maintain a proper pH (level of acidity).
Rich sources of phosphorus are soft drinks, milk, yogurt, ice cream, cheese, meat, poultry, eggs, grains, dried peas and beans, and some cereals and breads.
A shortage of phosphorus will eventually cause weakness, malaise, loss of appetite, and pain in the bones.
A surfeit of phosphorus can lead to hyperphosphatemia, which can have serious health consequences. Among these are skeletal porosity and calcium deposits in soft tissues, especially the lungs, stomach, and kidneys.
Your Daily Allowance
Diet Power sets your Personal Daily Allowance (PDA) of phosphorus at the Food and Nutrition Board's Recommended Dietary Allowance (RDA), measured in milligrams: 1250 for people aged 14* to 18, 700 for everyone over 18. The same figures apply for women 50 or younger who are pregnant or nursing. (In the rare event that you're over 50 and pregnant or nursing, Diet Power will assign you the 50-and-younger PDA for that reproductive state.)
The Tolerable Upper Intake Level (UL) of phosphorus is 4000 milligrams per day for children and adults aged 14* through 70. For people over 70 it drops to 3000 milligrams. For women who are pregnant, it's 3500 milligrams; for those who are lactating, 4000 milligrams. Getting more than the UL may harm your health.
The FNB notes, however, that "athletes and others with high energy expenditure frequently consume amounts from food greater than the UL without apparent effect."
* But remember that Diet Power is not designed for people under 15.
Revising Your Allowance
If your doctor recommends a different PDA, you can change it with the Personal Daily Allowance Editor.
Color Coding of This Nutrient
The phosphorus bar in your personal Nutrient History is:
· blue for "good" if you've logged 100 to 150 percent of your PDA
· red for "bad" if you've logged less than 100 percent of your PDA or more than the Tolerable Upper Intake Level (UL)
· yellow for "caution" if you've logged more than 150 percent of your PDA
· missing if you've logged no phosphorus.
In the nutrient profile of a food or recipe, the phosphorus bar is:
· green for "good" if getting your entire PDA of calories from this item would give you more than 150 percent of your PDA of phosphorus
· magenta for "bad" if getting all your calories from the item would give you less than 50 percent of your PDA of phosphorus
· blue for "neutral" otherwise
· missing if the amount of phosphorus is either zero or (when the word Phosphorus is grayed out) unknown.
How Complete Are Diet Power's Phosphorus Readings?
For the 8500 generic items in the Food Dictionary: very complete. Only 1 percent list their phosphorus content as "unknown."
For the 2500 chain-restaurant items: totally incomplete. All list phosphorus as "unknown."
For all 11,000 items combined: not terribly complete. About 21 percent list phosphorus as "unknown."
These figures mean that if you frequently log chain-restaurant foods (or user-added foods with missing phosphorus readings), your Nutrient History may underreport your intake of phosphorus by a few points.
To see whether a particular food has a phosphorus reading, open the Food Dictionary and check the food's nutrient profile. If you find a question mark beside "Phosphorus," it means the amount is unknown. (To see all foods with unknown phosphorus readings, click the dictionary's PowerFoods tab and sort the foods by phosphorus power; then scroll toward the bottom of the list until you see foods with question marks in the "Power Rating" column.)
Phosphorus on Food Labels
Food labels are not required to list phosphorus, although some do. They may cite the content in grams, milligrams, or percent of Daily Value.
The Daily Value for phosphorus is 1.0 gram, or 1000 milligrams. This amount is not necessarily right for you, however¾it's a rough estimate meant to accommodate most of the U.S. population.
For more on label regulations, see Labels, Food.