Calcium plays an essential role in the body. It helps to build strong bones and teeth, while also supporting the muscles, nerves, and heart. However, too much calcium can lead to problems.
In this article, we explore the symptoms, causes, and complications of hypercalcemia. We also describe how it can be diagnosed and treated.
Calcium levels in the blood are mostly controlled by the parathyroid glands. These four tiny glands sit behind the thyroid.
When the body needs calcium, the parathyroid glands secrete a hormone. This hormone signals:
- the bones to release calcium into the blood
- the kidneys to excrete less calcium into the urine
- the kidneys to activate vitamin D, which helps the digestive tract to absorb more calcium
Overactive parathyroid glands or an underlying health condition can disrupt the balance of calcium.
If calcium levels become too high, a person may be diagnosed with hypercalcemia. This condition can impede bodily functions, and may specifically be associated with:
- poor bone health
- kidney stones
- abnormal heart and brain function
Extremely high levels of calcium in the blood can become life-threatening.
Mild hypercalcemia may not result in symptoms, while more serious hypercalcemia can cause:
- Excessive thirst and frequent urination. Too much calcium means that the kidneys have to work harder. As a result, a person may urinate more often, leading to dehydration and increased thirst.
- Stomach pain and digestive problems. Too much calcium can cause an upset stomach, abdominal pain, nausea, vomiting, and constipation.
- Bone pain and muscle weakness. Hypercalcemia can cause the bones to release too much calcium, leaving them deficient. This abnormal bone activity can lead to pain and muscle weakness.
- Confusion, lethargy, and fatigue. Too much calcium in the blood can affect the brain, causing these symptoms.
- Anxiety and depression. Hypercalcemia may also affect mental health.
- High blood pressure and abnormal heart rhythms. High levels of calcium can increase blood pressure and lead to electrical abnormalities that change the heart’s rhythm, adding strain.
A number of factors and underlying conditions can cause hypercalcemia. These include:
OVERACTIVE PARATHYROID GLANDS:
The parathyroid glands control calcium levels. If they work too hard, this can lead to hypercalcemia.
The parathyroid glands may become overactive when one is enlarged or when a noncancerous growth forms on one.
Having overactive parathyroid glands is called hyperparathyroidism. This may be the most common cause of hypercalcemia.
Hyperparathyroidism is usually diagnosed in people aged between 50 and 60. It is also up to three times more common in women than men.
TOO MUCH VITAMIN D:
Vitamin D triggers calcium absorption in the gut. Once absorbed, calcium travels into the bloodstream.
Only 10–20 percent of the calcium in the diet is usually absorbed, while the rest is passed in stools. However, excessive amounts of vitamin D cause the body to absorb more calcium, leading to hypercalcemia.
In 2012, some researchers suggested that therapeutic high-dose vitamin D supplementation has the potential to cause hypercalcemia. These supplements can be used in the treatment of multiple sclerosisand other conditions.
The Food and Nutrition Board in the United States defines high doses of vitamin D as more than 4,000 international units (IU) per day. The recommended daily dose for adults is 600–800 IU per day.
If a person has cancer, this may cause hypercalcemia. Cancers that commonly lead to this condition include:
- lung cancer
- breast cancer
- blood cancers
In 2013, it was estimated that each year hypercalcemia affects more than 2 percentof all cancer patients in the U.S. Also, up to 30 percent of people with cancer will have high levels of calcium over the course of the disease.
If cancer spreads to the bone, this increases the risk of hypercalcemia.
People who are unable to move around for long periods may also be at risk for hypercalcemia. When the bones have less work to do, they can weaken and release more calcium into the bloodstream.
People who are severely dehydrated have less water in their blood, which can increase the concentration of calcium in the bloodstream. However, this imbalance is usually corrected once a person becomes sufficiently hydrated.
In some cases, high levels of calcium can lead to severe hydration. It is important for doctors to identify which came first: the high levels of calcium or the dehydration.
Some medications can overstimulate the parathyroid gland, and this can lead to hypercalcemia. One example is lithium, which is sometimes used to treat bipolar disorder.
Anyone experiencing symptoms of hypercalcemia should speak with a doctor, who will order a blood test and make a diagnosis based on results.
A person with mild hypercalcemia may have no symptoms, and the condition may only be diagnosed after a routine blood test.
The test will check for blood calcium and parathyroid hormone levels. These can show how well the body’s systems are functioning, such as those involving the blood and kidneys.
After diagnosing hypercalcemia, a doctor may perform further tests, such as:
- an ECG to record of the electrical activity of the heart
- a chest X-ray to check for lung cancer or infections
- a mammogram to check for breast cancer
- a CT or MRI scan to examine the body’s structure and organs
- dual energy X-ray absorptiometry, commonly known as a DEXA scan, to measure bone density.
Certain lifestyle changes can help to keep calcium levels balanced and bones healthy. These include:
- Drinking plenty of water. Staying hydrated may lower blood calcium levels, and it can help to prevent kidney stones.
- Quitting smoking. Smoking can increase bone loss. In addition to improving the health of the bones, quitting will reduce the risk of cancer and other health problems.
- Exercising and strength training. This promotes bone strength and health.
- Following guidelines for medications and supplements. Doing so may decrease the risk of consuming too much vitamin D and developing hypercalcemia.