Some athletes say that phosphorus helps improve endurance.
What Do the Advocates Say?*
Phosphate is an important component of the high-energy compounds essential for muscle function, as well as compounds that participate in oxygen delivery to muscle. Phosphates can also act as acid neutralizers, which might have effects on fatigue. Some studies have shown that phosphate supplementation improves endurance performance, but others have not.
*Athletes and fitness advocates may claim benefits for this supplement based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles.
Dosage & Side Effects
How Much Is Usually Taken by Athletes?
The use of alkalinizing agents, such as sodium bicarbonate, sodium citrate, and phosphate salts (potassium phosphate, sodium acid phosphate, and tribasic sodium phosphate) to enhance athletic performance is designed to neutralize the acids produced during exercise that may interfere with energy production or muscle contraction.1 Some double-blind studies, though not all, have found that sodium bicarbonate or sodium citrate typically improves exercise performance for events lasting either 1 to10 minutes or 30 to 60 minutes.2, 3, 4, 5, 6, 7, 8, 9, 10 The amounts used are 115 to 180 mg of sodium bicarbonate or 135 to 225 mg of sodium citrate per pound of body weight. These amounts are dissolved in at least two cups of fluid and are taken either as a single ingestion at least one hour before exercise or divided into smaller amounts and taken over several hours before exercise. Performance during periods of less than one minute or between 10 and 30 minutes is not improved by taking alkalinizing agents.11, 12, 13, 14, 15 Sodium citrate may be preferable to sodium bicarbonate because it causes less gastrointestinal upset.16 Another alkalinizing agent, phosphate salts, has been investigated primarily as an endurance performance enhancer, with very inconsistent results.17, 18
People with severe kidney disease must avoid excessive phosphorus. Based primarily on animal studies, some authorities have suggested that excess intake of phosphate is hazardous to normal calcium and bone metabolism,19 but this idea has been challenged.20 Phosphoric acid–containing soft drinks have been implicated in elevated kidney stone risk,21, 22 but not all studies have found this relationship.23
Ingestion of excessive amounts of aluminum-containing antacids (such as Di-Gel®, Riopan®, Maalox®, or Mylanta®) can cause phosphorus deficiency.
Interactions with Supplements, Foods, & Other Compounds
High phosphorus intake may impair absorption of iron, copper, and zinc.24Ingestion of excessive amounts of aluminum-containing antacids (such as Di-Gel, Riopan, Maalox, or Mylanta) can cause phosphorus deficiency.
Depletion of phosphorus may occur as a result of taking aluminum hydroxide. For those with kidney failure, reducing phosphorus absorption is the purpose of taking the drug, as excessive phosphorus levels can result from kidney failure. However, when people with normal kidney function take aluminum hydroxide for extended periods of time, it is possible to deplete phosphorus to unnaturally low levels.
Mineral oil has interfered with the absorption of many nutrients, including beta-carotene, calcium, phosphorus, potassium, and vitamins A, D, K, and E in some,25 but not all,26 research. Taking mineral oil on an empty stomach may reduce this interference. It makes sense to take a daily multivitamin-mineral supplement two hours before or after mineral oil. It is important to read labels, because many multivitamins do not contain vitamin K or contain inadequate (less than 100 mcg per day) amounts.
The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
People taking sucralfate may develop lower than normal blood levels of phosphorus.27 A 42-year-old woman who took sucralfate for two weeks experienced bone pain that was caused by low phosphorus levels. The bone pain disappeared after she stopped taking the drug and began supplementing with phosphorus.28 Individuals taking sucralfate should have their blood phosphorus levels monitored regularly by their healthcare practitioner and may need to take supplemental phosphorus.
Reduce Side Effects
Potential Negative Interaction
Where to Find It
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.
The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2015.
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