Vitamin D Testing: What you need to know

Check with your healthcare professional about vitamin D testing. If you think you may be suffering from vitamin D deficiency, get a blood test and ask for the results.

Some Introductory Remarks

Before you consider testing – be clear on why you want to do this, how you will interpret the information and what you will do once you know your results.

I recommend you first deterine what an optimum level of Vitamin D should be for you and your health objectives. Are you looking to load up on Vitamin D to deal with a specific health concern (i.e., reducing your risk of catching colds or flu?) or if going for a less specific goal of trying to improve your body's overall resistance to life-threatening diseases. In other words – be clear about your goals and objectives.

Before deciding when to take your test consider that Vitamin D levels will vary during the year. Generally, they are higher between May and September (if you live north of the equator) – when there is more sunshine, and lower in the other months when there is less sunshine – so when you take the test will affect your results.

Even more specifically, it you take the test after you've spent a weekend in the sun, you'll get higher readings than if you’ve been working indoors for three weeks in a row with little or no sunshine.

That said – I am certainly not against testing. In fact, testing for Vitamin D has been doubling each year for the past few years as more and more health problems are linked to vitamin D deficiency.

Vitamin D Testing Can Prevent 75% of Cancer Death

In the following video interview, the presenter makes a strong case for the testing of vitamin D levels as a way to determine and prevent risk of breast, colon and other cancers. According to the research Vitamin D testing and increasing your levels of vitamin D could prevent up to 75% of the deaths associated with these cancers.

Early Testing = Preventing Cancer Deaths

How Can I Order a Vitamin D Test and What Kind Should I Get?

The only blood test that can diagnose vitamin D deficiency is a 25-hydroxyvitamin D. Get your levels above 50 ng/ml (125 nmol/L) year-round.

If you have insurance, you can have your doctor order the test—some insurance companies will pay for a 25(OH)D test, some will not.

Unfortunately, about 20% of United States doctors order the wrong test. They order a 1,25-dihydroxy-vitamin D, thinking that by measuring the most potent steroid in the human body, calcitriol, they are getting useful information.

They are not. 1,25-dihydroxy-vitamin D is an adaptive hormone; it goes up and down with calcium intake. So these doctors see the 1,25-dihydroxy-vitamin D is normal or high and tell their patients that they are OK when really, they are vitamin D deficient—advice that may prove fatal.

Furthermore, most doctors who see a 25(OH)D of 30 ng/ml (75 nmol/L) will tell you that level is fine when it is not—that is, few doctors know how to correctly interpret the test results.

How the ZRT Home Test works

The Vitamin D Council has partnered with ZRT Labs to make a discounted take-home Vitamin D Test Kit that you can order on the Internet. A portion of the proceeds from the sale of each test will be donated to the Vitamin D Council by ZRT to help us in our mission to end the worldwide epidemic of vitamin D deficiency.

This is a home test for 25(OH)D, requiring a finger or heel stick to get several drops of blood. After receiving your kit either you, or someone you know in the medical field, will do a finger or heel stick and put the blood on the blotter included in the kit. You will then send the blotter paper back to ZRT in the envelope provided.

ZRT will perform the 25(OH)D test in their lab and send the results directly back to you. The Vitamin D Council has verified that results obtained by ZRT are accurate and correspond very well to the results given by both LabCorp and DiaSorin RIA. These tests are good for either adults or children and avoid the venipuncture many children dislike.

The tests will be available to order in either a quantity of one (1) or four (4). Whether you will be testing your entire family or simply retesting yourself, consider the 4 test kit as it is much less expensive per test.

With ZRT, you are in control of when you test, how often you test, and what you do with the results.

To order your test click here.

Interpreting the Results

A conventional doctor might think anywhere from 20–50 ng/mL is a normal level, but that recommendation will soon change as the newest research becomes incorporated into the standard of conventional care.

As always – your body, your age, your current health and circumstances that are unique to you should be considered in interpreting the results.

Here is a video prepared by a nutritionist that has some good information regarding recommended levels for optimal health.

Learn More About The Sunshine Vitamin

Vitamin D is important for good health and long-life. Here are some of the articles we've added to our website to give you a full picture of this important subject. Like other parts of this website these articles summarize the important facts and include useful advice.

If Vitamin D Were a Drug It Would Win the Nobel Prize

Benefits of Vitamin D

Vitamin D Deficiency: Causes and Risk Factors

Learn to recognize the symptoms of vitamin D deficiency, especially in women and children

Getting Vitamin D from Sunshine

Vitamin D from Food

What you need to know when choosing a Vitamin D supplement

Vitamin D Deficiency is linked to 2/3rds of the medical problems in the US along with poor diet

Vitamin D helps prevent 3 out 4 cancers

Vitamin D is Important for Good Heart Health

Vitamin D and Calcium: You Need Them Both

Vitamin D is important for heathy teeth and preventing periodontal disease and weakening of the jawbone

Vitamin D deficiency can cause mobility problems

Vitamin D and anti-aging


The information contained in this section of our web site is for educational purposes and is not intended as medical advice.

While the publishers of this website believe that people have the right to understand their own bodies and to take care of their bodies as they see fit, we also respect the knowledge and experience of trained nutritionists, scientists, researchers, medical practioners, and others who can help you achieve the optimum health you are entitled to, and suggest you seek out and work with health specialists you can trust.

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