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

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…


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New Research on Vitamin D Using Dried Blood Spot Testing

Two 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…


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Comparing Online Cardiovascular Disease Risk Assessment Tools

We’ve been hearing a lot about heart disease over the past few weeks as awareness of risk factors is actively promoted during American Heart Month in February. There are several risk factor assessment tools available online. While some basic information is common to all of them, there are differences in the factors included in the assessment, sometimes resulting in a different assessed risk…


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Celebrating Black History Month - An Interview with Naturopathic Dr. Kim Tippens

Dr. Kim Tippens, ND, MS, MPH is an integrative medicine researcher and professor with the National College of Natural Medicine in Portland, Oregon. She is an African American naturopathic doctor, a small minority in a profession dominated by white women. A survey of licensed naturopathic practitioners in two US states reported that 94% of NDs in Washington and 95% in Connecticut identified…


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Safer Sampling with ZRT Lab Testing Methods

The current concern over the dangerous Ebola virus has heightened awareness about infections that can be transmitted via contact with body fluids. The last thing we want is to be exposed to body fluids from others infected with dangerous organisms and, ironically, a likely place to encounter such fluids is the phlebotomy station at the doctor’s office. How can exposure to other people who may be…


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Breast Cancer - What Exactly Are We Talking About?

When asked what the number one risk factor for breast cancer is, founder and chief scientist of ZRT Laboratory Dr. David Zava has been known to say, “wearing a bra.” He's right. Why? Because having breasts, or just being a woman, is indeed the biggest risk factor, since the disease is 100 times more common in women than in men. is Breast Cancer Awareness month, but given the controversies that…


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The Strange Case of the Disappearing Hormone

I love mysteries. But unlike the advances in forensic science that have caused a sea change in solving murders previously only fathomable by sleuths such as Hercule Poirot, the advances in laboratory testing methods have outpaced the ability of the medical community to unravel the controversial mysteries surrounding absorption of steroid hormones. How did the Mystery Start? This ultimately stems…


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Have Persistent Skin Problems? Think Hormones

It certainly isn't news that hormones are involved in skin health. But it may be news that effects of declining estrogen levels are more obvious on the skin of the face than elsewhere on the body. How so? Read on. Lower Hormone Levels = Lower Skin Vitality. Women and their doctors have known for a long time that the decline in hormone levels as we age has a negative impact on skin properties, and we…


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Why Should We Care About Estrogen Metabolites?

Practical Takeaway: The liver's ability to properly metabolize estrogens has been found to affect the risk of breast cancer. Depending on which of the metabolic pathways predominate, too much of certain harmful estrogen metabolites (e.g., 4-hydroxy estrogens) can build up - and these have been found to correlate with breast and other hormone-dependent cancers.…


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How Hormones Lead to Obesity

Practical Takeaway: Imbalances in estrogen, testosterone, progesterone and cortisol, brought on by such factors as aging, diet and the stresses of modern life, have contributed to the obesity epidemic. Our bodies have also not adapted hormonally to the challenges of regulating fat stores when presented with excessive levels of highly refined foods found in the Western diet. Are Hormones Making Us…


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