Normal Blood Calcium Levels

Calcium is usually associated with healthy bones and teeth, but the calcium levels in your bloodstream impact your health overall. How do you know if you have a normal range of calcium in your blood, and what should you do if you don’t? The answer lies in the parathyroid gland

There are two pairs of parathyroid glands located next to the thyroid in the neck. These tiny glands regulate calcium levels in your blood. They do this by releasing the parathyroid hormone (PTH) if calcium levels begin to drop. PTH keeps blood calcium at normal levels by communicating with different organs of the body.

What Is the Normal Range of Calcium in the Blood?

Your body has a normal calcium level in the blood that it needs to operate at peak efficiency throughout your life. While everyone’s level may be slightly different, your parathyroid glands know precisely where your calcium needs to be. If your levels go higher or lower than their predetermined level, your parathyroid gland will quickly bring the calcium back to the correct amount. 

Your parathyroid cells contain calcium sensors on their surface. Just like you set the thermostat in your house, your genes set your sensors to ensure your body maintains the correct amount of calcium at all times. If calcium levels decline, the parathyroid hormone releases PTH to perform these functions:

  • Communicate with the bones to release more calcium into the bloodstream.
  • Tell the kidneys to pull calcium out of the urine and put it back in the blood.
  • Activate vitamin D within the kidneys, which goes directly to the intestines.
  • Use the increased vitamin D to trigger the intestines to absorb more calcium from food.

The Importance of Maintaining Normal Blood Calcium Levels

Calcium is an essential nutrient that affects every cell in the body. When normal blood calcium levels change, it can lead to:

  • Bone weakening, increasing your risk for fractures
  • Cognitive dysfunction, depression, and anxiety
  • Damage to the kidney and kidney stones
  • Increased blood pressure 
  • Heart palpitations and rhythm irregularities
  • Constipation, heartburn, and other digestive symptoms

In most cases, the parathyroid glands restore calcium levels before any real damage is done. If the levels are not corrected quickly, the negative effects can be severe. 

Why Do Blood Calcium Levels Change? 

Primary hyperparathyroidism (PHPT) is the most common reason normal calcium levels in the blood change. Primary PHPT occurs when one or more of the parathyroid glands start producing too much PTH. To understand why the glands might malfunction, we need to take another look at those calcium sensors on the parathyroid cells. 

Normal sensors are extremely efficient in managing the blood’s calcium levels. Problems arise when one or more of the cells becomes abnormal, usually because of a benign tumor (adenoma), or enlargement of the glands (hyperplasia). These changes alter the body’s natural calcium thermostat, leading to an overproduction of PTH and increased calcium levels (hypercalcemia).

There are other reasons why the normal range of calcium in the blood can change:

  • Calcium or vitamin D deficiency
  • Too much vitamin D
  • Chronic kidney failure
  • Cancer or diseases like tuberculosis & sarcoidosis
  • Some medications or supplements
  • Dehydration 

When calcium levels are affected by these factors, it is known as secondary parahyperparathyroidism. When the underlying medical condition is addressed, calcium levels typically stabilize as well. 

How Do I Know if My Calcium Levels Are Too High? 

It may be difficult to know if your calcium levels have changed due to PHPT, since symptoms can vary and some people don’t have any symptoms at all. Some common signs of PHPT include:

  • Extreme fatigue
  • Bone pain
  • Increased thirst
  • More frequent urination
  • Muscle weakness and pain
  • Difficulty concentrating
  • Poor sleep
  • Loss of appetite

If increased calcium levels persist, the symptoms may become more severe: 

  • Dehydration
  • Vomiting 
  • Confusion
  • Irregular heartbeat 

Severe cases of elevated calcium levels can lead to kidney failure, loss of consciousness, or life-threatening heart arrhythmias. 

Bringing Calcium Levels Back to Normal 

The first step to treating high calcium is to accurately diagnose it by measuring PTH and blood calcium levels. If both have risen, PHPT is the likely culprit. However, it is possible for the PTH levels to be higher while the calcium levels remain normal – a condition known as normocalcemic PHPT. You can also have elevated calcium levels with a normal PTH level, which is known as normohormonal PHPT.

Since diagnosis of PHPT is not always straightforward, it is a good idea to see a physician who specializes in the parathyroid and understands the nuances of the condition. If PHPT is the diagnosis, it is also critical to assess all four parathyroid glands for abnormalities. While it is most common to have only one gland affected, it is possible additional glands can be involved. In these cases, all affected glands require treatment to restore normal blood calcium levels.  

Schedule a Consultation With Dr. Larian

If you are concerned about abnormal blood calcium levels, Dr. Larian of the CENTER for Advanced Parathyroid Surgery can help. His expertise in the parathyroid ensures you receive the highest level of comprehensive care to maintain normal blood calcium levels. To learn more or schedule a consultation with Dr. Larian, please contact our office online or call us today at 310-461-0300.

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