Phosphorus
Phosphorus is the second most abundant mineral in the body, after calcium . About 85% of phosphorus in the body exists in bone.
Functions
Phosphorus’ functions include:
- Forming bones and teeth
- Growing, maintaining, and repairing of cells and tissues
- Synthesizing and activating proteins, such as enzymes and hormones
- Maintaining acid-base balance
- Producing, regulating, and transferring energy in the body
- Converting carbohydrates, protein, and fat into energy
- Important cell membrane component
- Important in hemoglobin’s oxygen delivery function
Recommended Intake
Age Group |
Recommended Dietary Allowance
(mg/day) |
---|---|
0-6 months | No RDA; Adequate Intake (AI) = 100 |
7-12 months | No RDA; AI = 275 |
1-3 years | 460 |
4-8 years | 500 |
9-18 years | 1250 |
19 years and older | 700 |
Pregnancy and lactation, 18 years and younger | 1250 |
Pregnancy and lactation, 19 years and older | 700 |
Phosphorus Deficiency
Phosphorus deficiency is called hypophosphatemia. Phosphorus is present in such a large variety of foods, however, that dietary phosphorus deficiency is rare.
Symptoms of hypophosphatemia may include:
- Loss of appetite
- Anemia
- Muscle weakness
- Bone pain
- Rickets
- Osteomalacia (softening of the bones)
- General debility
- Increased susceptibility to infection
- Paresthesias (prickling, tingling, or creeping of the skin) in the arm, hands, legs, or feet
- Ataxia (loss of voluntary muscular coordination)
Phosphorus Toxicity
Phosphorus toxicity is rare in people with normal kidney function. However, those with impaired kidney function may experience hyperphosphatemia, or elevated levels of phosphorus in the blood. Hyperphosphatemia can result in decreased levels of calcium in the blood and overproduction of parathyroid hormone, which can lead to bone loss. Calcium phosphate can deposit in various organs such as blood vessels, joints, lungs, kidneys. Hyperphosphatemia in kidney failure patients is a major cardiovascular risk factor.
Major Food Sources
The major food sources of phosphorus are milk, meats, poultry, fish, cereals, and legumes. About 20%-30% of dietary phosphorus comes from food additives.
Food | Serving Size |
Phosphorus Content
(mg) |
---|---|---|
Cornmeal, self-rising, degermed, enriched, yellow | 1 cup | 860 |
Milk, canned, condensed, sweetened | 1 cup | 774 |
Wheat flour, white, all-purpose, self-rising, enriched | 1 cup | 744 |
Oat bran, raw | 1 cup | 690 |
Trail mix, regular, with chocolate chips, salted nuts, and seeds | 1 cup | 565 |
Cheese sauce, prepared from recipe | 1 cup | 556 |
Milk, canned, evaporated, nonfat | 1 cup | 499 |
Biscuit with egg and sausage | 1 biscuit | 490 |
Pancakes with butter and syrup | 2 pancakes | 476 |
Baking powder, double-acting, straight phosphate | 1 teaspoon | 456 |
Halibut, Atlantic and Pacific, cooked, dry heat | ½ fillet | 453 |
Ricotta cheese, part skim milk | 1 cup | 450 |
Duck, domesticated, meat only, roasted | ½ duck | 449 |
Barley, pearled, raw | 1 cup | 442 |
Salmon, cooked, dry heat | ½ fillet | 428 |
Soybeans, mature cooked, boiled, without salt | 1 cup | 421 |
Bulgur, dry | 1 cup | 420 |
Sardine, Atlantic, canned in oil, drained solids with bone | 3 ounces | 417 |
Wheat flour, whole grain | 1 cup | 415 |
Pollock, walleye, cooked, dry heat | 3 ounces | 410 |
Buckwheat flour, whole groat | 1 cup | 404 |
Cheeseburger, large, single meat patty, with bacon and condiments | 1 sandwich | 400 |
Beef liver, pan-fried | 3 ounces | 392 |
Health Implications
Bone Health
Phosphorus plays an important role in the formation of bones. Levels of phosphorus in the body are closely tied to levels of calcium, another mineral instrumental for bone health. The kidneys work to maintain the proper ratio between these two minerals. One study, however, found that high dietary phosphorus can cause increased calcium loss, which, in turn, can cause a decrease in bone density and osteoporosis .
Tips for Lowering Your Phosphorus Intake
For most people, the kidneys regulate the amount of phosphorus in the body. But people whose kidneys are not functioning properly may need to limit the amount of phosphorus in their diets.
Dietary intake of phosphorus is difficult to limit because the mineral is found in so many foods. The following is a list of specific foods within larger food categories that contain particularly high levels of phosphorus and should be avoided.
- Dairy: Limit your daily intake of milk and milk products to one serving per day.
-
Meat:
- Fin fish such as salmon, pollock, walleye, flounder, sole, tuna, haddock, and swordfish
- Organ meats
-
Legumes:
- Dried beans
- Dried peas
- Dried lentils
- Nuts and seeds
-
Breads, grains, and cereals:
- Bran
- Brown rice
- Corn bread
- Granola
- Oatmeal
- Oat bran
- Pancakes
- Whole grain breads and cereals
- Wild rice
-
Vegetables:
- Corn
- Mushrooms
- Peas
-
Fruits:
- Avocado
- Coconut
-
Beverages:
- Beer
- Soda
RESOURCES:
American Dietetic Association
http://www.eatright.org
Food & Nutrition Information Center
United States Department of Agriculture
http://www.nal.usda.gov/fnic/
CANADIAN RESOURCES:
Canada's Food Guide
http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/index_e.html/
Dietitians of Canada
http://www.dietitians.ca/
References
Block GA, Port FK. Re-evaluation of risks associated with hyperphosphatemia and hyperparathyroidism in dialysis patients: Recommendations for a change in management. Am J Kidney Dis. 2000;3596:1226-1237.
Cannata-Andia JB, Rodriguez-Garcia M. Hyperphosphataemia as a cardiovascular risk factor-how to manage the problem. Nephrol Dial Transplant. 2002; 11:16-19.
Minerals: calcium, magnesium, phosphorus, and the electrolytes. In: Garrison RH Jr, Somer E. The Nutrition Desk Reference . New Canaan, CT: Keats Publishing; 1995:165-168.
Phosphorus. In: Standing Committee on the Evaluation of Dietary Reference Intakes Food and Nutrition Board Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride . Washington, DC: National Academy Press; 2000:146-189.
Phosphorus: Reducing it in your Diet. Mayo Foundation for Medical Education and Research website. Available at: http://www.mayoclinic.com . Accessed November 27, 2002.
Last reviewed April 2009 by David Juan, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.