Phosphorus

What Is Phosphorus?

Phosphorus makes up 1% of the average human's total body weight. Behind calcium, it is the most common mineral in the body. Phosphorus is an electrolyte. The other electrolytes include:

• Sodium
• Calcium
• Potassium
• Chloride
• Magnesium

Electrolytes like phosphorus in adequate amounts and ratios are necessary for the body to carry out a number of functions. Ensuring you have enough phosphorus through testing, therefore, is critical.

What Benefits Do Healthy Phosphorus Levels Provide?

Phosphorus provides several important health benefits. These include:

• Fluid regulation
• pH (acidity) normalization
• Muscle contraction
• Blood clotting
• Glucose (blood sugar) control
• Bone growth

Normal Phosphorus Ranges

The normal reference range for phosphorus counts, as determined by a phosphate test, is between 3.4-4.5 mg/dl (1.12-1.45 mmol/L). The proper phosphorus range differs between ages. Children under 5, for example, have 50% higher phosphorus levels on average compared to adults.

What Causes Low Phosphorus Levels?

Hypophosphatemia refers to unsafe, low levels of phosphorus. Conditions and practices that may result in hypophosphatemia include:

• Alcoholism
• Primary hyperparathyroidism (Excessive parathyroid hormone, PTH, causes the body to excrete too much phosphorus)
• Some common medications (more on pharmaceutical interactions with phosphorus below)
• Malabsorption from dietary intake

What Causes High Phosphorus Levels?

Unusually high phosphorus levels also indicate an underlying health issue that should be addressed. The serious medical condition of elevated phosphorus counts is called hyperphosphatemia. Hyperphosphatemia can be caused by:

• Hypoparathyroidism (too little parathyroid hormone produced by the parathyroid gland)
• Liver disease
• Diabetic ketoacidosis
• Some common medications (more on pharmaceutical interactions with phosphorus below)
• Renal disease (such as kidney failure)

The Kidneys and Phosphorus

The kidneys are responsible for normalizing phosphorus levels in the blood. Therefore, unusual readings from phosphorus blood tests are possible indicators of kidney disease. If you have abnormal phosphorus levels, further investigation of kidney function through additional testing is therefore recommended.

Who Should Order a Phosphorus Blood Test?

Patients with the following symptoms/conditions should consider ordering a phosphorus blood test to measure inorganic phosphate levels:

• Muscle weakness
• Malnutrition
• Diabetic ketoacidosis
• Kidney disease
• Liver disease
• Abnormal calcium levels (Too much calcium in the blood is called hypercalcemia)
• Known or suspected vitamin D deficiency

Vitamin D and Phosphorus

Vitamin D directly affects the amount of phosphorus and calcium supplies available to cells because it ferries the electrolytes, once they are digested, into the extracellular fluid.

Rickets and osteomalacia, which are associated with low phosphorus levels, are often caused by vitamin D deficiency. How much vitamin D is in the blood, therefore, is another critical marker of health.

Many Americans (as much as 75%) are deficient in vitamin D – which can directly impact the effective transport of phosphorus throughout the body. Patients may be well-advised to order a vitamin D test alongside their phosphorus test.

Pharmaceutical Medications May Interact With Phosphorus

Medications that can detrimentally impact circulating phosphorus levels include:

• Antacids
• Diuretics
• Laxatives

Unfortunately, medical advice from healthcare providers too often neglects the potentially harmful side effects of common pharmaceuticals in terms of maintaining optimal phosphorus levels. If you regularly take any of these medications, they may be adversely affecting your phosphorus levels. Assessing your phosphorus levels through a blood test, therefore, is recommended in these cases.

Where Can I Get a Phosphorus Test Near Me?

Visit Health Testing Center's Lab Locator to find a convenient testing location nearby. If you have questions, contact Health Testing Centers for additional information. We will provide the lab with the correct CPT code when needed.

Due to the COVID pandemic, our medical labs have instituted strict social distancing guidelines and mask-wearing guidelines. Please be prepared and plan accordingly. If you wish not to visit a local lab, we offer an extensive selection of test kits for your at home testing needs.

Sources:

"Disorders Involving Calcium, Phosphorus, and Magnesium." Primary Care. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2486454/
"Vitamin D Level Between Calcium-Phosphorus Homeostasis and Immune System: New Perspective in Osteoporosis." Current Osteoporosis Reports. https://pubmed.ncbi.nlm.nih.gov/27734322/
"Serum Inorganic Phosphorus." Clinical Methods: The History, Physical, and Laboratory Examinations. https://www.ncbi.nlm.nih.gov/books/NBK310/
"Association of serum phosphate levels with glucose tolerance, insulin sensitivity and insulin secretion in non-diabetic subjects." European Journal of Clinical Nutrition. https://pubmed.ncbi.nlm.nih.gov/16391583/
"Phosphorus Regulation in Chronic Kidney Disease." Methodist Debakey Cardiovascular Journal. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347182/
"Phosphorus and the Kidney: What Is Known and What Is Needed." Advances in Nutrition. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3884106/

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Oct 12, 2020