Phosphorus is the second most abundant mineral in the body, after calcium. About 85% of phosphorus in the body exists in bone.

Phosphorus’ functions include:

• Forming bones and teeth
• Growing, maintaining, and repairing of cells and tissues
• Synthesizing and activating proteins, such as enzymes and hormones
• Maintaining acid-base balance
• Producing, regulating, and transferring energy in the body
• Converting carbohydrates, protein, and fat into energy
• Important cell membrane component
• Important in hemoglobin’s oxygen delivery function

Phosphorus deficiency is called hypophosphatemia. Since phosphorus is present in such a large variety of foods, dietary phosphorus deficiency is rare.

Symptoms of hypophosphatemia may include:

• Loss of appetite
• Anemia
• Muscle weakness
• Bone pain
• Rickets and osteomalacia, which is a softening of the bones
• Increased susceptibility to infection
• Prickling, tingling, or creeping of the skin in the arm, hands, legs, or feet
• Loss of muscular coordination

Phosphorus toxicity is rare in people with normal kidney function. However, those with kidney problems may experience hyperphosphatemia, or elevated levels of phosphorus in the blood. Hyperphosphatemia can result in decreased levels of calcium in the blood and overproduction of parathyroid hormone, which can lead to bone loss.

The following table shows the upper intake levels for phosphorus. But, it's important to note that these levels are not created for people with kidney disease. If you have problems with your kidneys and are concerned about your phosphorus intake, talk to your doctor.

Are you looking to add more phosphorus to your diet? Here are some good food sources: