Health Benefits of Phosphorus

Phosphorus is an essential mineral present in every cell in the body. It’s an important component of the bones, teeth, and adenosine triphosphate (ATP), the body’s main energy source. It’s also needed for nerve, muscle, kidneys, and heart functioning.

Phosphorus exists in the body as phosphate, a compound that contains phosphorus and other substances, which is why phosphorus and phosphate are often used interchangeably in the medical field.

Phosphorus is concentrated in many foods, such as dairy products, fish, poultry, nuts, and beans. Deficiencies in phosphorus are rare, and most people don’t need to take supplements. However, supplemental phosphorus may be necessary for some, such as those with low phosphorus intake and people with certain medical conditions.

Phosphorus supplements in stores aren’t the same as phosphorus-based medications, like K-Phos, which are sometimes used to treat conditions like urinary tract infections and kidney stones. 

Necessary for Certain People 

Some people are more at risk for developing low phosphorus levels, known as hypophosphatemia in the medical field. Hypophosphatemia is when blood levels of phosphorus fall below 2.5 milligrams per deciliter (mg/dL). Low phosphorus usually develops due to inadequate dietary phosphorus intake, increased phosphorus excretion, or as a result of certain medical conditions.

Eating Disorders and Severe Malnutrition

Nearly all diets provide enough phosphorus to maintain optimal levels. However, people who don’t take in enough overall calories, such as those with eating disorders like anorexia nervosa and bulimia nervosa, can develop low phosphorus levels, which may need to be treated with supplemental phosphorus.

For example, one study of 307 people with anorexia nervosa (AN) or avoidant/restrictive food intake disorder (ARFID) who were admitted to an eating disorder treatment center found that 44% of the participants with ARFID and 33% of participants with anorexia had hypophosphatemia at the time of admission.

People with severe malnutrition can also develop refeeding syndrome, a condition that occurs when nutrients are suddenly reintroduced after a long period of starvation. This causes cells to take up all available phosphate and leads to severe hypophosphatemia.

Other Medical Conditions

People with medical conditions that cause intestinal malabsorption may also develop low phosphorus levels as can people taking medications that bind with phosphorus and increase its excretion from the body. One example is glucocorticoid medications, commonly used to treat inflammatory bowel disease (IBD).

Certain medical conditions, such as chronic diarrhea, rare genetic disorders of phosphorus metabolism, hyperparathyroidism, kidney tubule defects, and diabetic ketoacidosis, as well as critical illness, can also cause phosphorus deficiencies.

Depending on the cause of low phosphorus levels, healthcare providers might administer supplemental phosphorus through a vein or prescribe oral phosphorus supplements to increase levels safely. 

May Improve Athletic Performance in Elite Athletes

Some research suggests that short-term phosphorus supplementation may improve athletic performance in endurance athletes. Several studies have found that phosphorus supplements may improve power output, oxygen uptake, and aerobic capacity in cyclists and runners. 

Phosphorus supplements may improve athletic performance by enhancing ATP availability and oxygen consumption by the heart. 

For example, one study found that six days of supplementing with 50 mg of tri-sodium phosphate per kilogram (kg) of fat-free mass decreased heart rate, improved the oxygen consumed per heartbeat, and increased stroke volume (the amount of blood pumped out of the left ventricle of the heart per beat) during an exercise test performed in a low-oxygen environment.

Another study in cyclists also found that in the participants who were more sensitive to phosphate supplementation, treatment with 50 mg per kilogram (kg) of fat-free mass of tri-sodium phosphate per day for six days significantly increased aerobic performance by 3-5%. Other studies have found that short-term phosphate supplementation improved exercise performance in cyclists and runners.

However, study findings are mixed. Some studies have found that supplementing with phosphate had no benefit on athletic performance. Therefore, it’s unclear if phosphate supplements offer a significant benefit to athletes.

Good Sources of Phosphorus

Phosphorus is found in both plant and animal foods. Here are some of the best food sources of phosphorus:

• Lentils: 356 milligrams (mg) per cup, or 28% of your Daily Value (DV)
• Low-fat yogurt: 245 mg per 6 ounces (oz), or 20% of your DV
• Milk, 2%: 226 mg per cup, or 18% DV 
• Salmon: 214 mg per 3 oz, or 17% of your DV
• Brown rice: 204 mg per cup, or 16% of your DV
• Mozzarella, skim: 197 mg per 1.5 oz, or 16% of your DV
• Green peas: 188 mg per cup, or 16% of your DV
• Chicken breast: 182 mg per 3 oz, or 15% of your DV
• Ground beef: 172 mg per 3 oz, or 14% of your DV

Phosphorus is also found in smaller amounts in foods like eggs, oats, sesame seeds, potatoes, and cashew nuts. 

Because phosphorus is so plentiful in the diet and is found in both animal and plant foods, most people take in enough phosphorus to meet their daily requirements, even if they’re following a more restrictive diet, such as a vegetarian diet. 

How To Take Phosphorus 

Phosphorus can be found in multivitamins and phosphorus-only supplements, though phosphorus-only supplements aren’t as common. Phosphorus-only supplements that contain high doses of phosphorus are usually prescribed by healthcare providers to treat low phosphorus levels and aren’t appropriate for the average person.

The most common forms of phosphorus used in supplements are phosphate salts, such as dipotassium phosphate and disodium phosphate, both of which are relatively well absorbed by the body.

Most supplements, such as multivitamins, only provide a small amount of phosphorus per serving, usually 10% of the DV or less. However, some supplements, such as phosphorus-only supplements, may provide 100% or more.

If your healthcare provider finds that you have low phosphorus levels or if you have a medical condition that puts you at risk for developing a phosphorus deficiency, they may prescribe oral phosphorus supplements to safely increase your levels. If you’re prescribed phosphorus, your healthcare provider will give you specific instructions on dosing and how to take your supplement.

You shouldn’t take over-the-counter (OTC) high-dose phosphorus supplements unless specifically prescribed and monitored by your healthcare provider. 

Dosage 

The current Recommended Dietary Allowance (RDA) for phosphorus is 700 mg for adults over the age of 19. This is for total phosphorus intake from both food and supplements. Dosing for phosphorus supplements varies. 

If you’re prescribed phosphorus due to a medical condition or low phosphorus levels, your healthcare provider will recommend a total daily dose and dosing schedule, as phosphorus supplements are usually taken in multiple doses throughout the day. 

Is Phosphorus Safe?

Supplemental phosphorus is usually safe for healthy people, even in high doses.

However, you shouldn’t take supplemental phosphorus in high doses unless prescribed by a healthcare provider. Taking excessively high doses, such as over 6,000mg of sodium phosphate in one day, could result in high blood levels of phosphorus, also known as hyperphosphatemia. The main side effects include calcification of certain tissues, including the kidneys, and changes in the hormones that regulate calcium metabolism.

Hyperphosphatemia can also occur in people who cannot excrete extra phosphorus in their urine, such as those with kidney disease. Normally, your kidneys excrete 90% of your daily phosphate load, but people with kidney disease cannot properly excrete excess phosphorus.

People with advanced kidney disease often need to restrict high-phosphorus foods and avoid phosphorus-containing supplements to prevent phosphorus buildup in their bodies. Several other medical conditions, such as hypoparathyroidism and genetic deficiencies, can also cause hyperphosphatemia.

Phosphate salts like sodium phosphate may also damage the intestines in people with inflammatory gastrointestinal (GI) conditions or bowel obstructions.

People with these health conditions should avoid taking phosphorus supplements unless specifically prescribed by their healthcare provider. 

Potential Drug Interactions

Phosphorus supplements may interact with several medications, including: 

• Balversa (erdafitinib): Erdafitinib is a cancer medication that increases phosphate levels in the blood. Taking phosphate salts, such as dipotassium phosphate and disodium phosphate, at the same time as this medication could result in dangerously high phosphate levels. 
• Bisphosphonates: Bisphosphonates are medications that reduce bone density loss. Both bisphosphonates and phosphate salts can reduce calcium levels in the body and taking them together can cause very low calcium levels, which can be dangerous to health. 

Other medications may interact with phosphorus supplements. Ask your healthcare provider about potential interactions. 

To support optimal absorption, phosphorus supplements should be taken at least two hours apart from other mineral supplements, such as iron, calcium, and magnesium.

What To Look For 

Most people don’t need to take supplemental phosphorus. People that have low phosphorus levels are usually treated with prescription products.

However, if you’re interested in purchasing an OTC supplement that contains phosphorus, it’s important to choose products from trusted companies. When possible, it’s best to purchase supplements certified by USP, UL, and NSF International. These independent organizations set strict standards for supplement quality and safety.

Can You Take Too Much Phosphorus?

Unless specifically prescribed by your healthcare provider, you shouldn’t take dietary supplements containing high phosphorus levels. Most healthy people take in plenty of phosphorus from their diet and don’t require supplemental phosphorus to maintain healthy levels.

The Tolerable Upper Intake Level (UL), the maximum daily intake of a nutrient unlikely to cause harm, is currently set at 4,000 mg per day for adults aged 19-70 and 3,000 mg per day for adults over 71. The UL for pregnant people is set at 3,500 mg per day.

The UL for phosphorus applies to both food and supplements. However, the ULs do not apply to people who take phosphorus supplements prescribed and monitored by a healthcare provider.

Side Effects of Phosphorus 

Phosphorus supplements may result in a few side effects, most of which affect the digestive system. Here are a few possible side effects that may occur when taking phosphorus supplements:

• Stomach upset
• Diarrhea
• Headache

If you experience any side effects when taking phosphorus supplements, contact your healthcare provider.

A Quick Review

Phosphorus supplements are sometimes prescribed to people who develop low phosphorus levels due to a medical condition or low phosphorus intake. Typically, a healthcare provider prescribes phosphorus to people with low phosphorus levels.

Phosphorus is also available in multivitamin supplements and in phosphorus-only supplements. However, most people don’t need to take supplemental phosphorus as it’s found in many plant and animal foods.

In general, healthy people don’t need to supplement with phosphorus. However, if you’re interested in taking a phosphorus-containing product, it’s best to consult your healthcare provider to make sure it’s a safe and appropriate choice for your health needs.