Phosphorus is a mineral that helps build bones and teeth and helps cells make energy. Most people in the US get more than they need, so the main concern is too much, especially in kidney disease.
Here are the NIH figures and safety points.
Daily phosphorus requirement
Average daily recommended amount (mg):
- Children 1 to 3 years: 460 mg
- Children 4 to 8 years: 500 mg
- Children 9 to 13 years: 1,250 mg
- Teens 14 to 18 years: 1,250 mg
- Adults 19 and older: 700 mg (also in pregnancy and breastfeeding)
Upper limit from all sources (mg per day): children 1 to 8: 3,000, ages 9 to 70: 4,000, adults over 70: 3,000, pregnant women: 3,500.
Best food sources of phosphorus
Good sources include:
- Dairy such as milk, yogurt and cheese
- Meat, poultry, fish and eggs
- Bread, brown rice and oatmeal
- Nuts and seeds such as cashews and sesame seeds
- Lentils, kidney beans, peas, potatoes and asparagus
Many processed foods also contain phosphorus additives such as phosphoric acid and sodium phosphate.
Phosphorus deficiency
Deficiency is rare. Signs include loss of appetite, anemia, muscle weakness, coordination problems, bone pain, soft deformed bones, more infections and confusion. Higher risk: premature babies, people with certain rare genetic disorders and people with severe malnutrition.
Too much phosphorus and kidney disease
High intake seldom causes problems in healthy people. In severe chronic kidney disease, phosphorus can build up in the blood and harm bones and worsen kidney disease. People with kidney disease should follow the diet and medicines their doctor or dietitian prescribes.
Medicine interactions
Antacids containing aluminum hydroxide or calcium carbonate reduce phosphorus absorption, and using them for 3 months or longer can lead to low phosphorus. Some laxatives with sodium phosphate can raise phosphorus levels, and taking more than the directed dose can be dangerous, especially with dehydration, kidney disease or heart disease.
Frequently Asked Questions
How much phosphorus do adults need per day?
Adults need 700 mg per day.
What is the upper limit for phosphorus?
4,000 mg per day for adults aged 19 to 70, and 3,000 mg per day for adults over 70.
Which foods are rich in phosphorus?
Dairy, meat, poultry, fish, eggs, whole grains, nuts, seeds and legumes, plus processed foods with phosphate additives.
Who should limit phosphorus?
People with severe chronic kidney disease, as advised by their doctor or dietitian.
Do antacids affect phosphorus?
Yes. Antacids with aluminum hydroxide or calcium carbonate reduce absorption, and long-term use can lead to low phosphorus.
Related reading: Calcium daily needs and supplement safety | Magnesium daily needs | Vitamin D daily needs
Sources
Medical disclaimer: this article is for general information and does not replace advice from a qualified doctor. Do not start, stop or change any supplement or medicine without medical advice.