The ZRT Laboratory Blog

The ZRT Blog is an extensive resource for patients and health care providers searching for health and hormone testing information. Here, you can read about ZRT’s cutting edge research, advances in testing, wellness advice, and health industry highlights.

How Reference Ranges Determine a "Normal" Lab Test Result

Posted by Margaret Groves on Friday, 13 November

normal.chalkboard.jpgCLIA-certified testing laboratories such as ZRT are required to provide reference ranges as an aid to interpretation of test results.

Ideally, reference ranges provide the expected range of values for a healthy population. When methodology and equipment is identical for testing a particular analyte among different laboratories, reference ranges for that analyte should be the same.

However, when methodologies or equipment for the same test differ somewhat from lab to lab, each lab must provide its own reference range established with its own methods. These ranges are usually very close, but may differ slightly depending on method. An example would be testing testosterone in blood or saliva by extraction and LC-mass spectrometry vs. direct testing by immunoassay.

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Clearing up the Confusion about Reverse T3: Part 2. The Role of Reverse T3 in Thyroid Assessment

Posted by Margaret Groves on Friday, 08 May

ThinkstockPhotos-467771145Part 2

As more health care practitioners have understood the need to assess thyroid function based on what is going on at the cellular level, there has been an increasing demand for testing of reverse T3 (rT3), a hormone sometimes referred to as the “hibernation hormone.” However, there is also much confusion about how it fits into the picture of thyroid function, and controversy regarding whether or not there is a clinical utility for this test in patients suffering from thyroid imbalance symptoms.

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Clearing up Confusion about Reverse T3: Part 1. The Deiodinases & Thyroid Hormone Bioavailability

Posted by Margaret Groves on Monday, 04 May

ThyroidPart One

Thyroid hormones are essential for the normal metabolic functioning of all tissues in the body, and a wide array of symptoms are therefore associated with abnormalities in thyroid hormone production and activation. Even when apparently adequate amounts of thyroxine are produced by the thyroid gland, thyroid function is profoundly affected by anything that disrupts conversion of thyroxine (T4) to the active thyroid hormone, triiodothyronine (T3). This conversion takes place primarily at the cellular level within tissues; only 20% of circulating T3 is generated by conversion of T4 within the thyroid gland itself.

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New Research on Vitamin D Using Dried Blood Spot Testing

Posted by Margaret Groves on Thursday, 23 April

Vitamin DTwo vitamin D studies were published recently, both utilizing ZRT's testing in dried blood spot.

Dried blood spot samples are well suited for research applications because they are equivalent to serum but have the advantage of ease of sample collection, shipping, and storage, which doesn’t require any refrigeration or biohazard labeling. Also, samples are easily identified by details that can simply be written on the outside flap of the collection cards, which require minimal freezer space for long-term storage of samples.

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