Phosphorus

Also indexed as: Phosphate

What is it?

Phosphorus is an essential mineral that is usually found in nature combined with oxygen as phosphate. Most of the phosphate in the human body is in bone, but phosphate-containing molecules (phospholipids) are also important components of cell membranes and lipoprotein particles, such as HDL and LDL (“good” and “bad” cholesterols, respectively). Small amounts of phosphate play important roles in numerous biochemical reactions throughout the body.

The role of phosphate-containing molecules in aerobic exercise reactions has suggested that phosphate loading might enhance athletic performance, though controlled research has produced inconsistent results.1 2

Where is it found?

Phosphorus is highest in protein-rich foods and cereal grains. In addition, phosphorus additives are used in many soft drinks and packaged foods. Phosphorus is not often present in supplements except for certain calcium supplements, such as bone meal.

Phosphorus has been used in connection with the following condition (refer to the individual health concern for complete information):

Rating Health Concerns
2Stars

Osteoporosis (for elderly people taking calcium supplements)
1Star

Athletic performance
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Who is likely to be deficient?

Phosphorus deficiency is uncommon, because dietary intake is usually adequate.3 Chronic alcoholics may become deficient in phosphorus.4 and people taking large amounts of aluminium-containing antacids5

One study has shown that taking calcium can interfere with the absorption of phosphorus, which, like calcium, is important for bone health.6 . Although most western diets contain ample or even excessive amounts of phosphorus, older people who supplement with large amounts of calcium may be at risk of developing phosphorus deficiency. For this reason, the authors of this study recommend that, for elderly people, at least some of the supplemental calcium be taken in the form of tricalcium phosphate or some other phosphorus-containing preparation.

How much is usually taken?

Phosphorus supplements are unnecessary. Most multiple vitamin-mineral supplements do not contain phosphorus for this reason.

Are there any side effects or interactions?

People with severe kidney disease must avoid excessive phosphorus. High phosphorus intake may impair absorption of iron, copper, and zinc.7 Based primarily on animal studies, some authorities have suggested that excess intake of phosphate is hazardous to normal calcium and bone metabolism,8 but this idea has been challenged.9 Phosphoric acid–containing soft drinks have been implicated in elevated kidney stone risk,10 11 but not all studies have found this relationship.12

Ingestion of excessive amounts of aluminium-containing antacids (such as Di-Gel®, Riopan®, Maalox®, or Mylanta®) can cause phosphorus deficiency.

Are there any drug interactions?
Certain medicines may interact with phosphorus. Refer to drug interactions for a list of those medicines.

References

1. Galloway SD, Tremblay MS, Sexsmith JR, Roberts CJ. The effects of acute phosphate supplementation in subjects of different aerobic fitness levels. Eur J Appl Physiol 1996;72:224–30.

2. Tremblay MS, Galloway SD, Sexsmith JR. Ergogenic effects of phosphate loading: physiological fact or methodological fiction? Can J Appl Physiol 1994;19:1–11.

3. Pennington JA, Schoen SA. Total diet study: estimated dietary intakes of nutritional elements, 1982–1991. Int J Vitam Nutr Res 1996;66:350–62.

4. Knochel JP, Agarwal R. Hypophosphatemia and hyperphosphatemia. In Brenner B, ed. The Kidney, 5th ed. Philadelphia: WB Saunders, 1996, 1086–133 [review].

5. Lotz M, Zisman E, Bartter FC. Evidence for a phosphorus-depletion syndrome in man. N Engl J Med 1968;278:409–15.

6. Heaney RP, Nordin BEC. Calcium effects on phosphorus absorption: implications for the prevention and co-therapy of osteoporosis. J Am Coll Nutr 2002;21:239–44.

7. Bour NJS, Soullier BA, Zemel MB. Effect of level and form of phosphorus and level of calcium intake on zinc, iron, and copper bioavailability in man. Nutr Res 1984;4:371–9.

8. Calvo MS, Park YK. Changing phosphorus content of the U.S. diet: potential for adverse effects on bone. J Nutr 1996;126:1168S–80S [review].

9. Standing Committee on the Scientific 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, 1997, 181–6 [review].

10. Shuster J, Jenkins A, Logan C, et al. Soft drink consumption and urinary stone recurrence: a randomized prevention trial. J Clin Epidemiol 1992;45:911–6.

11. Rodgers A. Effect of cola consumption on urinary biochemical and physicochemical risk factors associated with calcium oxalate urolithiasis. Urol Res 1999;27:77–81.

12. Curhan GC, Willett WC, Rimm EB, et al. Prospective study of beverage use and the risk of kidney stones. Am J Epidemiol 1996;143:240–7.