Make sure you distinguish your D's!

From Dr. Joseph Mercola:

Drisdol and Calcitriol are synthetic forms of vitamin D2; the form of vitamin D typically prescribed by doctors.

But this is not the type produced by your body in response to sun or safe tanning bed exposure.

A recent meta-analysis by the Cochrane Database looked at mortality rates for people who supplemented their diets with D2 versus those who did so with D3, the form naturally produced by your body.

The analysis of 50 randomized controlled trials, which included a total of 94,000 participants, showed:

• A six percent relative risk reduction among those who used vitamin D3, but
• A two percent relative risk increase among those who used D2

In an article posted on Live in the Now, Dr. John J. Cannell writes:

"Amazingly, this study somehow slipped under the radar...

You would think a paper that took a look at tens of thousands of subjects and analyzed the efficacy of prescription vitamin D (D2) and over-the-counter vitamin D (D3) would warrant a news story or two.

To my knowledge, these papers are the first to paint such a clear picture about the efficacy between D3 and D2."

The Two Types of Vitamin D

Supplemental vitamin D comes in two forms:

1. Ergocalciferol (vitamin D2)
    
2. Cholecalciferol (vitamin D3)

They have long been regarded as equivalent and interchangeable, especially since a recognized vitamin D expert, Dr. Michael Hollick, recommended it. But that notion was based on studies of rickets prevention in infants conducted several decades ago. Today, we know a lot more about vitamin D, and the featured study offers compelling support for the recommendation to take vitamin D3 if you need to take an oral supplement—which is the same type of D vitamin created in your body when you expose your skin to sunlight.

According to the latest research, D3 is approximately 87 percent more potent in raising and maintaining vitamin D concentrations and produces 2- to 3-fold greater storage of vitamin D than does D2. Regardless of which form you use, your body must convert it into a more active form, and vitamin D3 is converted 500 percent faster than vitamin D2. Vitamin D2 also has a shorter shelf life, and its metabolites bind poorly with proteins, further hampering its effectiveness.

Unfortunately, vitamin D2—which is a synthetic version made by irradiating fungus and plant matter—is the form of vitamin D most often prescribed by doctors in the U.S. Hopefully this will change sooner rather than later.

As stated by Dr. Cannell in the featured article:

"While there may be explanations for D3's superiority other than improved efficacy, for the time being, these papers send doctors a message: use D3, not D2."

By the way, Mercola shares a lot more good information on the referenced page about vitamin D and its uses.