Phosphorus Deficency and Toxicity

Phosphorus Deficiency

Phosphorus deficiency due to diet is rare. Because phosphorus is found in the cell membranes of both animals and plants, phosphorus is plentiful in a very wide range of foods. Phosphorus is also commonly used as a food additive.

More likely causes of hypophosphatemia--low blood levels of phosphorus-- might include any of the following:

• Starvation
• Prolonged vomiting
• Wasting away illness
• Long-term intravenous feeding without sufficient phosphates
• Excess use of phosphate-binding antacids
• Prolonged excess stress
• Recent surgery
• Liver disease
• Hyperparathyroidism
• Diabetic acidosis
• Alcoholism

Symptoms associated with phosphorus deficiency vary, depending on the severity of the condition and length of time. Typical symptoms can include any of the following:

• Weakness
• Lack of appetite
• Anemia
• Nausea and vomiting
• Mental confusion
• Bone pain and easily broken bones (due to loss of calcium)

When the deficiency is more pronounced (phosphorus serum level below 1.5 mg/dL), the condition can be life threatening. Impaired white cell function reduced cardiac output and cardiac arrhythmias, skeletal muscle, and cardiac myopathy, and ataxia (lack of muscle coordination) are some of the possibilities.

Phosphorus deficiency, once assessed by a physician, is treated with a high phosphorus diet and phosphorus containing supplements, as needed.

Phosphorus Toxicity

Phosphorus toxicity, as manifested by hyperphosphatemia—high blood levels of phosphorus- sometimes occurs as the result of long-term adherence to a low calcium/high phosphate diet. This unhealthy combination leads to increased secretion of the parathyroid hormone (PTH), which in turn results in increased bone turnover, decreased bone mass and density, and susceptibility to fractures.

As with phosphorus deficiency, the symptoms of toxicity vary for different individuals. Depending on the degree of toxicity, any of the following additional symptoms may be exhibited.

• Muscle spasms
• Calcification of soft tissues, especially kidneys, which can lead to kidney damage
• Seizures
• Cardiac arrhythmias
• Shortness of breath

Since severe toxicity can be life-threatening, it must be carefully monitored and treated by a physician thoroughly trained in this area.  Mildly elevated blood levels of phosphorus may have already started to affect bones, so to keep the condition from worsening, major dietary changes may be in order. For example, people who eat a lot of fast foods and processed foods and take in an insufficient amount of calcium compared to the excess phosphorus could be compromising their health. Those who persist in eating that way every day will in time probably not only have an elevated phosphorus blood level but the experience accelerated bone demineralization.