What is it?
People use phosphate salts for medicine. Be careful not to confuse phosphate salts with substances such as organophosphates, or with tribasic sodium phosphates and tribasic potassium phosphates, which are very poisonous.
Phosphate salts are taken by mouth for treating blood phosphate levels that are too low and blood calcium levels that are too high, and for preventing kidney stones. They are also taken for treating osteomalacia (often called “rickets” in children), a condition caused by a mineral imbalance in the body that leads to softening of the bones. Phosphate salts are also used for improving exercise performance, as an antacid for gastroesophageal reflux disease (GERD), and as a laxative for emptying the bowels before surgery.
Phosphate salts and calcium are applied to sensitive teeth to reduce pain.
Rectally, phosphate salts are used as a laxative to clean the bowels before surgery or intestinal tests.
Healthcare providers sometimes give potassium phosphate intravenously (by IV) for treating low phosphate and high calcium levels in the blood, and for preventing low phosphate in patients who are being tube-fed.
How effective is it?
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
The effectiveness ratings for PHOSPHATE SALTS are as follows:
- Correcting low blood phosphate levels, when sodium and potassium phosphates are taken by mouth or given intravenously (by IV) by a healthcare provider.
Likely effective for...
- Correcting high blood calcium levels, when sodium and potassium phosphates are used.
Possibly effective for...
- Preventing some types of kidney stones.
Likely ineffective for...
- Improving aerobic exercise performance.
Insufficient evidence to rate effectiveness for...
- Sensitive teeth.
- Cleaning out the bowels as a laxative preparation for intestinal tests such as colonoscopy when sodium phosphates are used.
- Other conditions.
How does it work?
Are there safety concerns?
Regular long-term use can upset the balance of phosphates and other chemicals in the body and should be monitored by a healthcare professional to avoid serious side effects. Phosphate salts can irritate the digestive tract and cause stomach upset, diarrhea, constipation, and other problems.
Do not confuse phosphate salts with substances such as organophosphates, or with tribasic sodium phosphates and tribasic potassium phosphates, which are very poisonous.
Special precautions & warnings:Pregnancy and breast-feeding: Phosphate salts from dietary sources are LIKELY SAFE for pregnant or breast-feeding women when used at the recommended allowances of 1250 mg daily for mothers between 14-18 years of age and 700 mg daily for those over 18 years of age. Other amounts should only be used with the advice and ongoing care of a healthcare professional.
Children: Phosphate salts are LIKELY SAFE for children when used at the recommended daily allowances of 460 mg for children 1-3 years of age; 500 mg for children 4-8 years of age; and 1250 mg for children 9-18 years of age. Phosphate salts can be UNSAFE if phosphate consumed (expressed as phosphorous) exceeds the tolerable upper intake level (UL). The ULs are 3 grams per day for children 1-8 years; and 4 grams per day for children 9 years and older.
Heart disease: Avoid using phosphate salts that contain sodium if you have heart disease.
Fluid retention (edema): Avoid using phosphate salts that contain sodium if you have cirrhosis, heart failure, or other conditions that can cause edema.
High levels of calcium in the blood (hypercalcemia): Use phosphate salts cautiously if you have hypercalcemia. Too much phosphate could cause calcium to be deposited where it shouldn’t be in your body.
High levels of phosphate in the blood: People with Addison's disease, severe heart and lung disease, kidney disease, thyroid problems, or liver disease are more likely than other people to develop too much phosphate in their blood when they take phosphate salts. Use phosphate salts only with the advice and ongoing care of a healthcare professional if you have one of these conditions.
Kidney disease: Use phosphate salts only with the advice and ongoing care of a healthcare professional if you have kidney problems.
Are there interactions with medications?
- Bisphosphonate medications and phosphate salts can both lower calcium levels in the body. Taking large amounts of phosphate salts might cause calcium levels to become too low.
Some bisphosphonates include alendronate (Fosamax), etidronate (Didronel), risedronate (Actonel), tiludronate (Skelid), and others.
Are there interactions with herbs and supplements?
- Calcium, iron, and magnesium
- Phosphate can combine with calcium, iron, or magnesium. This reduces the body's ability to absorb phosphate, calcium, iron, and magnesium. To avoid this interaction, phosphate should be taken at least 2 hours before or after taking calcium, iron, or magnesium.
Are there interactions with foods?
- There are no known interactions with foods.
What dose is used?
- For raising phosphate levels that are too low or lowering calcium levels that are too high: Healthcare providers measure the levels of phosphate and calcium in the blood and give just enough phosphate to correct the problem.
The adequate intakes (AI) for infants are: 100 mg for infants 0-6 months old and 275 mg for infants 7-12 months of age.
Tolerable Upper Intake Levels (UL), the highest intake level at which no unwanted side effects are expected, for phosphate (expressed as phosphorus) per day are: children 1-8 years, 3 grams per day; children and adults 9-70 years, 4 grams; adults older than 70 years, 3 grams; pregnant women 14-50 years, 3.5 grams; and breast-feeding women 14-50 years, 4 grams.
To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.
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