Next to calcium, phosphorus is the most abundant mineral in the body. These two important nutrients work closely together to build strong bones and teeth. Approximately 85% of phosphorus in the body can be found in bones and teeth and roughly 10% circulates in the bloodstream. The remaining phosphorous can be found in cells and tissues throughout the body. Phosphorous helps filter out waste in the kidneys and contributes to energy production in the body by participating in the breakdown of carbohydrates, protein, and fats. It also helps reduce muscle pain after a hard workout. Phosphorus is needed for the growth, maintenance, and repair of all tissues and cells, and for the production of the genetic building blocks, DNA and RNA. Phosphorus is also needed to balance and metabolize other vitamins and minerals, including vitamin D, calcium, iodine, magnesium, and zinc.

Phosphorous deficiencies can be caused by excessive intake of aluminum containing agents (such as certain antacids) because the aluminum can bind to phosphorous. In addition, diabetes, starvation, alcoholism, and conditions that can cause abnormal absorption of nutrients (such as Crohn's disease, celiac disease, and radiation damage) can lead to depletion of phosphorous in the body. Symptoms of phosphate deficiency include loss of appetite, anxiety, bone pain, bone fragility, stiffness in the joints, fatigue, irregular breathing, irritability, numbness, weakness, and weight change. In children, decreased growth and poor bone and tooth development may occur.

Having too much phosphorous in the body is actually more common and more worrisome than having too little of this mineral. Excessive phosphorous is generally caused by kidney disease or by consuming too much dietary phosphorous relative to dietary calcium. As dietary phosphorous increases, the need for additional calcium rises as well. The delicate balance between calcium and phosphorous is necessary for proper bone density and prevention of osteoporosis.

Because most foods contain sufficient amounts of phosphorus, additional supplementation with this mineral is not generally necessary. Sometimes athletes use phosphate supplements before competitions or heavy workouts to help reduce muscle pain and fatigue. Phosphorus and calcium can be used together to help heal bone fractures and to treat bone disorders caused by vitamin D deficiencies, namely osteomalacia and rickets (softening and weakening of the bones in adults and children respectively).

Protein-rich foods, such as meat, poultry, fish, eggs, dairy products, nuts, and legumes are particularly good sources of phosphorus. Other sources include whole grains, hard potatoes, dried fruit, garlic cloves, and carbonated beverages.

Elemental phosphorus, a white or yellow waxy substance that burns on contact with air is highly toxic and no longer used in medicine. (Although, it is used in some homeopathic treatments and should be taken only under the guidance of a qualified practitioner). Instead, health care providers may recommend using one or more of the following inorganic phosphates, which are not toxic:

• Dibasic potassium phosphate
• Monobasic potassium phosphate
• Dibasic sodium phosphate
• Monobasic sodium phosphate
• Tribasic sodium phosphate

Daily recommendations for dietary phosphorous are listed below:

Pediatric

• Infants 0 to 6 months: 100 mg (adequate intake)
• Infants 7 to 12 months: 275 mg (adequate intake)
• Children 1 to 3 years: 460 mg (RDA)
• Children 4 to 8 years: 500 mg (RDA)
• Children 9 to 18 years: 1,250 mg (RDA)

Adult

• 19 years and older: 700 mg (RDA)
• Pregnant and breastfeeding females under 18 years: 1,250 mg (RDA)
• Pregnant and breastfeeding females 19 years and older: 700 mg (RDA)

Because of the potential for side effects and interactions with medications, dietary supplements should be taken only under the supervision of a knowledgeable healthcare provider.

Too much phosphate can lead to diarrhea and calcification (hardening) of organs and soft tissue, and can interfere with the body's ability to use iron, calcium, magnesium, and zinc. Athletes and others taking supplements that contain phosphate, should only do so very occasionally and with the guidance/direction of a health care provider.

Nutritionists recommend a balance of calcium and phosphorus in the diet. The typical Western diet, however, is imbalanced in these minerals. Most people who consume this type of diet consume roughly two to four times more phosphorus than calcium. For example, meat and poultry contain 10 to 20 times as much phosphorus as calcium, and carbonated beverages such as colas have as much as 500 mg of phosphorus in one serving. When there is more phosphorus than calcium in the system, the body will draw on calcium stored in bones. This can lead to reduced bone mass (namely, osteopenia or osteoporosis) that makes bones brittle and fragile. It can also lead to gum and teeth problems. A balance of dietary calcium and phosphorus can lower the risk of osteoporosis, and relieve the symptoms of osteoarthritis and other problems related to the body's ability to use calcium.

High doses of insulin may decrease blood levels of phosphorus in people with diabetic ketoacidosis (a condition caused by severe insulin insufficiency). This serious condition is treated in a hospital and replacement of phosphorous takes place under the direction of a physician.

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