Vitamin D

VITAMIN D Testing and Benefits

Adapted to sun Snail
A snail getting a tan

In a nutshell, vitamin D is so important to humans (and other animals) Mother Nature makes it easy to get. The fact is, your own body can make vitamin D simply by exposing your skin to the sun (in a safe way, of course). For decades, however, we’ve been warned away from sun exposure, even though it's our best source of vitamin D. As a result, millions of us are now seriously vitamin D deficient (Gloria and I call it VDD).

VDD has been linked to diseases we sometimes think are just part of living —conditions such as these:

  • asthma
  • heart disease and stroke
  • multiple sclerosis (and other auto-immune diseases)
  • osteoporosis
  • osteopoenia (weakening of the bones)
  • blood pressure issues
  • de-mineralization of the small bones in the inner ear
  • rickets (which, by the way, is on the increase in North America)
  • brain tissue deterioration¹
  • weak immunity
  • diabetes
  • and cancer

No one yet knows how to predict whether you are likely to experience disease as a result of vitamin D deficiency, but science does know you stand an unwelcome chance.

The year 2010 was a good year for vitamin D research, with well over 1,500 papers published. Their bottom line is that vitamin D deficiency may well be linked to an extremely wide range of diseases. It's clear: the last thing you want is a vitamin D deficiency.


Molecular structure of Vitamin D
Molecular Structure of Vitamin D

How do you know whether you have enough vitamin D? Consider that your body works with sunlight to produce vitamin D, then ask yourself, “Am I exposing large areas of bare skin (arms, legs, back) to sunlight 15-20 minutes a day, 365 days a year, and without sunblock? And if I'm not, am I taking vitamin D3 supplements?"

If the answer is no to both questions, and if you follow a typical North American diet and lifestyle, there’s a good chance you’re VDD.

So if you suspect you are VDD, visit your doctor and insist (yes, insist) on the 25 OH Vitamin D Test.

You know what? Even if you don't suspect you might be VDD, we recommend you take the test anyway, because vitamin D is so significant to your health and deficiency is so wide spread.


The 25-hydroxyvitamin D test is administered through a blood sample and reported as “nanograms per liter” (ng/ml) in the U.S.A. and as “nanomolecules per liter” (nmol/l) in Canada.

50-80 ng/ml or 125-200 nmol/l are considered good levels. Be aware, however, there is ongoing debate about levels.

Some guidelines recommend “minimum” or “normal” levels (20- 56 ng/ml or 50-140 nmol), but don’t consider them your target. Here’s why: You want enough vitamin D in your body for immediate use and for storage against the day when your body just can’t synthesize any vitamin D.

Consider, too, that your body’s fat and muscle tissues won’t even begin storing vitamin D until you have 40-50 ng/ml. That’s one clear indication your body wants the stuff available all the time, every day, every month, all year long—get it? Use this information to discuss optimum levels for you with your doctor. And don't take vitamin D for granted!

Check out our vitamin D blog posts for a lot more information and discussion, and read Chapter 10 "Do It Yourself Vitamins" in EAT TO SAVE YOUR LIFE.

2. Harvard School of Pubic Health. "Vitamins."


Freaky Fact

According to the Harvard School of Public Health, 57% of patients admitted to a Boston hospital were shown to be deficient in vitamin D (2006)².

Related Supplements

Vitamin D3 with vitamin K2 is critical for bone health. Vitamin D3 is a superior form, and preferable to vitamin D2.
Eat to Save Your Life BookEat to Save Your Life answers the hard nutrition questions.

Buy it now!