We all know calcium is important for good health, but too much of it in your blood can signal a problem. If a blood test shows elevated calcium levels, it may mean your body is pulling too much calcium from your bones.
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This can happen when one of your parathyroid glands malfunctions. You may experience “brain fog” or perhaps feel more achy if you have this condition, called primary hyperparathyroidism. But many people don’t notice any symptoms.
“Although very high calcium can make patients feel poorly, that is actually quite rare in parathyroid disease,” says endocrinologist Susan Williams, MD.
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How does your body balance calcium levels?
There are four small parathyroid glands directly behind the thyroid gland in your neck. These regulate levels of calcium and phosphorus in the body.
Having the proper amount of calcium in your blood is vitally important, Dr. Williams says.
Your body has two ways to make sure there is always enough.
1. It absorbs calcium from the foods and beverages in your diet
Once calcium enters your bloodstream from your intestinal tract, your body processes it in various ways:
- Some calcium remains in the bloodstream
- Your bones absorb some
- Your body excretes the excess
2. If necessary, your body will take calcium from your bones
Your bones are a kind of built-in storage system for calcium. If your body doesn’t get what it needs from your diet, your parathyroid glands secrete parathyroid hormone. This signals the bones to release calcium into circulation.
The only place the body stores calcium is in your bones. Calcium absorbed into the bone becomes part of the bone matrix. There, it helps make bones strong and fracture-resistant.
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Routine testing for calcium
The serum calcium blood test is routinely done as part of a basic blood sample test, Dr. Williams says.
If there is high calcium in the blood, this test will detect it. In fact, the condition is most often revealed through routine blood tests performed for other reasons.
If you have a mild case of this condition (calcium serum levels are slightly elevated), doctors typically monitor the situation, testing your blood about every six months. In the meantime, drinking plenty of water can help keep calcium levels near normal.
In diagnosing hyperparathyroidism, your doctor also looks for elevated parathyroid hormone in the blood test. This is important because the serum calcium level alone does not tell the physician where your body is getting its calcium, Dr. Williams says.
Your body relies on getting sufficient calcium from your diet, but when that does not happen, the parathyroid glands release parathyroid hormone. This tells your body to release calcium from your bones. This is your body’s workaround – it’s a way of keeping the blood (serum) calcium in the normal range.
Low or low-normal calcium levels are often seen in vitamin D deficiency, Dr. Williams says. Vitamin D is also important as it helps the body absorb calcium in the intestines.
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What happens when things go wrong?
Over time, hyperparathyroidism can weaken bones and cause kidney stones.
“Knowing how they work, it’s not a far stretch of the imagination to understand that if a parathyroid gland becomes overactive, it can result in too much calcium being in our blood,” Dr. Williams says.
If your body retains excessive amounts of calcium, it would typically end up in your blood system, which means you have high serum calcium. In hyperparathyroidism, one or more of the glands becomes overactive and will sometimes become enlarged, known as a parathyroid adenoma.
Doctors don’t refer to overactive parathyroid glands as tumors in clinical practice. They are known only as adenomas, Dr. Williams says. Typically, doctors treat hyperparathyroidism by removing the adenoma. But not all patients need surgery, she says.
The best way to safeguard the balance of calcium in your body? Be mindful that you are getting calcium through dietary sources – dairy products and foods fortified with calcium are best; dark leafy greens such as kale are also beneficial.
Also, be sure to visit your doctor for routine preventive care. Many times, hyperparathyroidism has no symptoms, and getting blood tests annually as part of your routine physical exam is important.