Low or high blood calcium levels must be evaluated carefully during testing for hyperparathyroidism (HPT). Here are key factors that can impact the results of a parathyroid hormone (PTH) blood test.

1. Time of Day

Research indicates PTH levels can start to rise after 6:00 p.m., reach their peak levels between 2:00 a.m., and fall to their baseline values. PTH levels can then again peak around 6 a.m., decline to baseline at 8:00 a.m. and then again peak at about 10:00 a.m.

Morning represents the best time to accurately measure calcium in the blood. This can increase the likelihood of getting accurate calcium blood test results.

The body’s PTH level rises naturally at different times during the day. This occurs due to bone remodeling.

Bone remodeling is ongoing. Each time bones remodel themselves, they are replaced by two types of cells: osteoblasts and osteoclasts. Osteoblasts form new bones, while osteoclasts destroy them.

PTH activates osteoclasts. If a parathyroid gland malfunctions, the body’s PTH and calcium levels can rise, which impacts bone formation and destruction.

With a morning test, a patient can reduce their risk of measuring the amount of calcium in the body at a time when their PTH level is temporarily elevated. If a doctor finds a patient’s PTH or calcium levels are elevated following a morning test, additional assessments can be performed to verify if one or more parathyroid glands is defective.

2. Biotin

Biotin, aka vitamin B7, helps the body break down carbohydrates, fats, and other substances.

People can take biotin supplements that support skin, hair, eyes, liver, and nervous system health. They can also obtain biotin via bananas, eggs, and other foods, according to Healthline. Conversely, an excess amount of biotin in the blood can cause some lab test results to be falsely increased or decreased.

In one study, researchers found an excess amount of biotin can cause abnormal parathyroid laboratory test results. They noted these results can put an emotional strain on a patient and lead to potentially harmful and unnecessary medical interventions.

3. Medications

Certain medications have been shown to contribute to high blood calcium levels. These medications include lithium, diuretics, calcium carbonate, and vitamin D supplements.

Comparatively, research indicates medications like bisphosphonates, Prolia, and Sensipar can cause blood calcium levels to decline.

4. Diet and Nutrition

Fasting is recommended for about 10 to 12 hours before a PTH blood test. During this time, patients should only drink water.

By fasting, nutrients in various foods will not potentially disrupt PTH blood test results. Furthermore, consuming caffeine, alcohol, and/or tobacco can skew the results of a PTH blood test.

Do You Need a PTH Blood Test?

A PTH blood test can be used to identify causes of abnormal calcium or phosphorus levels. The test can be performed if a patient is dealing with abnormal calcium or phosphorus levels in the blood. It can also be recommended if a patient is coping with fatigue, nausea, or other physical symptoms associated with high or low calcium levels.

During a PTH blood test, a doctor collects a blood sample from their patient. Next, the doctor analyzes the test results.

The results of a PTH blood test are available within a few days. At this time, the doctor determines if their patient’s PTH level is low, high, or normal.

A doctor may recommend additional evaluations to validate their patient’s PTH blood test results. He or she can also perform calcium and vitamin D blood tests. In doing so, the doctor can determine if their patient’s parathyroid is functioning correctly. And the doctor can look for signs of high calcium in their patient’s blood.

Causes of High Calcium in Blood

Mayo Clinic notes causes of high calcium include HPT, cancer, and various diseases. High blood calcium levels have also been linked to genetic disorders, severe dehydration, medications, supplements, and immobility.

Those dealing with a high blood calcium level may be diagnosed with hypercalcemia. Along with a PTH test, other assessments may be performed to verify the root cause of too much calcium in the blood.

What Causes Low Blood Calcium?

Research shows common low calcium causes include hypothyroidism, a vitamin D deficiency, and kidney dysfunction. People who experience a low blood calcium level may be diagnosed with a calcium deficiency. But calcium deficiency causes vary, and a PTH test and other assessments may be required to properly diagnose and treat a low blood calcium level.

How to Achieve a Normal Range for a PTH Blood Test

The normal range for a PTH blood test falls between 14 and 65 pg/mL, according to Dr. Babak Larian of the CENTER for Advanced Parathyroid Surgery in Beverly Hills, but can differ slightly between each testing laboratory.

Dr. Larian helps his patients prepare for a PTH blood test to achieve accurate results. If Dr. Larian finds a patient’s blood calcium level is above- or below-average, he can perform additional assessments. And if Dr. Larian discovers one or more of his patient’s parathyroid glands is malfunctioning, he can perform a minimally invasive parathyroidectomy (MIP).

An MIP can cure HPT, with minimal risk to thyroid, vocal cord nerves, blood vessels, and various organs and tissue. Dr. Larian applies local anesthetic to limit pain during the procedure. He then makes a small incision into his patient’s neck and removes any malfunctioning parathyroid glands.

Dr. Larian can complete an MIP in about 20 minutes. Following an MIP, Dr. Larian ensures that his patient’s blood calcium level returns to a normal range. He also conducts a 4 gland assessment to find out if the procedure was successful.

Learn More About PTH Testing and Blood Calcium Levels

The parathyroid glands produce PTH that manages the body’s calcium level. But tumors can develop on one or more of the parathyroid glands that hinder PTH production. In these instances, the calcium in the blood can exceed or fall below a normal level. This can lead to a calcium imbalance, along with HPT that causes osteoporosis, kidney stones, and other physical symptoms.

Dr. Larian can help patients dealing with a high or low blood calcium level. He can determine if his patient’s above- or below-average blood calcium level can be attributed to HPT. And Dr. Larian can determine if an MIP can be used to alleviate this issue. To learn more, book your appointment with Dr. Larian today.

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