High Serum Calcium And Phosphorus

The majority of calcium and phosphorus is found in your bone. Small amounts of the minerals, approximately 1 percent of each, circulate through your blood. Because the amount of calcium and phosphorus in your blood is so low, the concentration must be tightly maintained to prevent any health problems. According to Dr. Leonard Deftos of Endotext.org, disorders of calcium, phosphorus and the skeletal system are some of the most common diseases a doctor will encounter during his practice.

Calcium and Phosphorus Balance

Calcium and phosphorus form a delicate balance, and your body uses a number of different mechanisms to maintain this balance. Normal serum calcium falls between 8.5 to 10.2 milligrams per deciliter, or mg/dL, while normal serum phosphorus falls between 2.4 to 4.1 mg/dL. If your blood calcium levels decrease, your parathyroid glands release parathyroid hormone, which triggers the bone to release calcium and phosphorus, increasing the levels of both minerals in your blood. When your blood calcium levels increase, parathyroid hormone production decreases, and the thyroid gland releases calcitonin, which stops the release of calcium and phosphorus from the bone and increases the excretion of calcium in your urine.

Hypercalcemia

If the system that balances calcium and phosphorus levels is disrupted, it can lead to high serum calcium, or hypercalcemia. One of the most common causes of high serum calcium is hyperparathyroidism, a condition in which the parathyroid glands release too much parathyroid hormone. The excess parathyroid hormones trigger the bone to continuously release calcium and phosphorus, even when the levels of the minerals in the blood are normal or high. Over time, the loss of these minerals from the bone leads to loss of bone structure and decreased bone density, which increase the risk of bone fractures and osteoporosis.

Types of Hyperparathyroidism

Hyperparathyroidism is divided into two categories, based on its cause. Primary hyperparathyroidism occurs when one or more of the parathyroid glands are enlarged. In primary hyperparathyroidism, serum phosphorus levels drop as serum calcium levels rise. Secondary hyperparathyroidism occurs as a complication of another underlying condition. In secondary hyperparathyroidism, calcium and phosphorus levels rise simultaneously.

Hyperphosphatemia

A significant increase in phosphorus levels is referred to as hyperphosphatemia. Typically, hyperphosphatemia occurs as a result of kidney failure, hypoparathyroidism or diabetic ketoacidosis, but may also be seen in secondary hyperparathyroidism. Levels of phosphorus in the blood may also increase as a result of excess phosphorus supplementation.

When blood phosphorus levels are high, the mineral can combine with calcium to form calcium phosphate. This compound can accumulate in the tissues of your organs, leading to calcification, or hardening of the tissues. If left untreated, this calcification can lead to organ damage.

Complications

When the levels of calcium and phosphorus in your blood are abnormally high, the kidneys work extra hard to remove the excess minerals and maintain normal serum concentration. This can put too much stress on the kidneys, eventually leading to kidney damage. If left untreated, the kidneys can fail, completely losing their ability to remove calcium and phosphorus from the blood.