Vitamin D vs D3: What’s the Difference? | Trio Nutrition

It’s easy to get confused when you’re researching vitamins due to all the types and variations available. For instance, there are eight types of B vitamins, plus multiple types of iron, C and magnesium, and that’s just a handful of nutrients you might find on any given nutrition label. So, it should come as no surprise that there are two forms of vitamin D as well: D2 and D3.

What is the difference between vitamin D2 and vitamin D3, and which should you be taking? We’re going to talk about it in detail, including what they are, where they come from and how to ensure you're taking the right D vitamin for you. 

What Types of Vitamin D Are There? 

Vitamin D is a fat-soluble vitamin that comes in two forms, D2 and D3. It’s common to see D2 simply called vitamin D, while the other form of D is referred to as D3. No matter what you call it, though, D vitamins are essential to good health. Our bodies need them to facilitate calcium absorption, maintain bone health, support our immune system and other vital cellular functions. 

What’s the difference between vitamin D2 and vitamin D3?

Vitamin D is sometimes called the sunshine vitamin, and for good reason. Our bodies produce D3 when our skin is exposed to the sun caused by a reaction between the ultraviolet B rays (UVB) and a form of cholesterol in the skin. D3 is also available in some animal-based foods. Vitamin D2 can be found in some types of plants. 

Technically, there is very little difference in D2 and D3. While the sources are different, each is metabolized by the liver into calcifediol. This metabolite form is called the “active form” of vitamin D and this is what blood tests are looking for when checking vitamin D levels. Some studies indicate that D3 is more effective at raising our blood’s level of vitamin D. This makes vitamin D3 the more usable form when comparing supplement options.

Where Do You Get Vitamin D From? 

When your skin is exposed to the sun, you produce vitamin D3, so getting this particular form of the vitamin is as easy as getting a little sun. But you can also consume vitamin D3 by eating some animal-based foods, including: 

• Liver
• Organ meats
• Fatty fish (i.e. salmon, tuna, trout, mackerel) 
• Fish oil 
• Egg yolks 

Vitamin D2 is often used to fortify foods since it is less expensive to manufacture. You can also find it in some plant-based foods. The following are natural and fortified sources of vitamin D2:

• Wild mushrooms 
• Fortified milk
• Fortified cereal products
• Fortified orange juice 

Which Form of Vitamin D is Best?

While they are similar in many ways, vitamin D3 appears to be more effective at raising your body’s level of this essential nutrient.

How To Take a Vitamin D Supplement

Vitamin D insufficiency and deficiency are somewhat common, so it’s important to try to get it from several sources to ensure you have enough. If your diet allows for meat, consuming foods like liver, egg yolks and fatty fish a couple of times a week may be a good idea to boost Vitamin D levels, as long as your doctor hasn't told you to avoid such foods. 

Of course, taking a vitamin D3 supplement along with a well-balanced diet can be a good way to ensure you have all your bases covered. The following tips can help you get the most out of your vitamin supplement:

• Take consistently for best results, preferably at the same time of day.
• Opt for a high-quality D3 supplement over D2 versions.
• Take with magnesium to improve conversion of D into an active, usable form. 
• Take with a meal if possible for best absorption.

And while variables like your age, ethnicity and sun-exposure play into how much you should supplement with, the average minimum daily recommendation is 400–800 IU, or 10–20 micro grams, according to the National Institutes of Health (NIH). You may need more than this, so consult your doctor if you think you may have a vitamin D deficiency.

At the end of the day, vitamin D3 is the winner when you’re looking for increased levels of active vitamin D and overall bioavailability. While your body can make D3 when you get enough sun, many people are deficient in this key vitamin. While you can try to get more time in the sun and consume more vitamin D rich foods, supplementation may be the quickest and most convenient way to make sure your body has all the vitamin D it needs.

*The information in this article and throughout Trio Nutrition’s blog is for informational purposes only, and should never be mistaken for professional medical advice.