Vitamin D2

Vitamin D2 is also called ergocalciferol. (wow, big word!)

It comes primarily from plant and fungal sources, such as mushrooms, and it is also used in some fortified foods and supplements.

Yes, D2 works. Your body can use it to help maintain vitamin D levels.

But studies have generally found that D2 doesn’t raise and maintain vitamin D levels in the blood quite as effectively as D3.

That brings us to the one you’ll probably see most often on the supplement shelf.

Vitamin D3

Vitamin D3 is also called cholecalciferol. (OMG, another one of those big words!)

D3 is the form commonly found in vitamin D supplements and generally does a better job than D2 of maintaining vitamin D levels in the body.

But here’s the interesting part.

D3 is also the form of vitamin D our own bodies make when our skin is exposed to sunlight.

So, Is Sunshine Vitamin D?

Here’s the kicker….Not exactly.

The sunshine itself doesn’t contain vitamin D and put it into your body.

Instead, ultraviolet B — usually called UVB — light from the sun reaches your skin and starts a chemical process. Your body then produces vitamin D3. In other words:

Sunshine doesn’t give us vitamin D. It helps our bodies make it.

Then What Happens to It?

Whether your vitamin D comes from sunshine, D2, or D3, your body still has to put it to work.

First, your liver changes it into a form that can be measured in your blood.

That is the number your doctor usually looks at when you have a vitamin D blood test.

From there, your body changes some of it again into the form it can actually use.

And what does it use vitamin D for?

One of its biggest jobs is helping your body absorb calcium, which is important for strong bones and healthy muscles.

Can’t We Just Get Enough From the Sun?

Maybe. But it isn’t quite that simple.

How much vitamin D your skin produces depends on quite a few things, including:

• Your age

• Where you live

• The season

• Time of day

• How much skin is exposed

• Skin pigmentation

• Sunscreen and clothing

And as we get older, our skin generally becomes less efficient at producing vitamin D from sunlight.

That’s one reason it can be difficult to say something simple like, “Spend 15 minutes in the sun every day and you’ll get enough vitamin D.”

It just doesn’t work the same way for everybody.

There is also another side to it. Too much exposure to ultraviolet light can damage the skin and increase the risk of skin cancer. So deliberately spending long periods in the sun without protection isn’t a particularly good vitamin D strategy.

So Which Is Better — D2, D3 or Sunshine?

They aren’t really three competing choices.

Here’s the simple version:

Vitamin D2: Your body can use it, but it generally doesn’t maintain vitamin D levels as effectively as D3.

Vitamin D3: Our bodies can use both D2 and D3, but D3 generally does a better job of raising and maintaining vitamin D levels.

Sunshine: Helps your skin naturally manufacture vitamin D3, but the amount you produce can vary considerably.

And perhaps the most important point is this:

You don’t have to guess whether you’re getting enough vitamin D.

A simple blood test can measure your vitamin D level. If there is a reason to be concerned about yours, that number gives you and your healthcare provider something much more useful to work with than trying to calculate how much sunshine you got last Tuesday.

The Simply Sage Takeaway

Vitamin D sounds complicated because we hear about D2, D3, supplements, sunshine and blood levels as though they are all different subjects.

They really aren’t.

D2 and D3 are simply two forms of vitamin D. Our bodies can use both, but D3 generally does a better job of maintaining vitamin D levels. And sunshine? It doesn’t actually give us vitamin D — it helps our bodies make D3 naturally.

Sometimes understanding just that much makes the whole subject a little simpler.

Want to know a little more?
The National Institutes of Health has an easy-to-read Vitamin D Fact Sheet with more information about vitamin D, sunshine, supplements and recommended amounts.

This article is for general information and isn’t intended to replace advice from your healthcare provider.

Simple is not where you start, simple is where you arrive!