In general, most people consume more than enough phosphorus in the diet.³ It is present in high quantities in milk, other protein sources and grains. Additionally, it is added to many beverages and packaged foods.

Phosphorus deficiency may develop in certain circumstances, however. People with severe alcoholism may become deficient in phosphorus as well as other basic nutrients; deficiency may also occur in people with kidney failure, parathyroid dysfunction or poorly controlled diabetes.⁴

Therapeutic Dosages

In studies of phosphate for enhancing sports performance, a one-time dose of one gram of tribasic sodium phosphate has been the most common dose.

For ongoing use as treatment for osteoporosis, advocates recommend that phosphate be taken as part of a calcium product that includes phosphate, such as milk products or the supplement tricalcium phosphate.

Therapeutic Uses

Because phosphate plays a fundamental role in the body's energy-producing pathways, it has been suggested that taking high doses of phosphate (phosphate loading) prior to athletic activities might enhance performance. Phosphate-containing chemicals are also part of the process that allows oxygen release from hemoglobin, and this too has intrigued researchers looking for ergogenic aids. However, while some studies have found that phosphate loading improves maximum oxygen utilization, others have not, and flaws in study design cast doubt on the positive results.^1-2,6-7

Although it has long been stated that high phosphorus intake due to consumption of soft drinks might lead to osteoporosis, there is no solid evidence for this claim; in fact, elevated intake of phosphorus may help prevent osteoporosis.⁵ The reason for that is that bone contains both calcium and phosphate.

Safety Issues

In general, phosphorus is a safe nutritional substance.

One-time high intake of some forms of phosphate may cause diarrhea. It is also possible that ongoing intake of phosphorus at high levels may impair absorption of copper, iron and zinc.⁸

Some evidence hints that excessive consumption of phosphorus in the form of soft drinks might increase kidney stone risk, but study results are contradictory, and if there is an effect it appears to be small.^9-11

Individuals with severe kidney disease should avoid phosphorus supplements, just as they must avoid taking too much of many other minerals.