Vitamin D2 vs D3: What’s The Difference?

Wouldn’t it be great if getting enough vitamin D was as simple as lounging in the sun? Well, it actually is! But, rather unfortunately, the majority of us either live in cloudy countries or are locked away at work when the sun does eventually come out. Supplementing with vitamin D can consequently be essential for our overall health. 

Sounds nice and simple, right? Well, what if we told you that there are two types of vitamin D, and they’re not quite the same. There’s vitamin D2 and vitamin D3, and there’s plenty to discuss when it comes to their sources, effectiveness and quality. So, let’s dive into the differences to help you become that bit more supplement savvy. 

What is Vitamin D?

Vitamin D, often called the “sunshine vitamin,” earns its nickname because your body produces it when your skin is exposed to sunlight. It’s a fat-soluble vitamin that plays a crucial role in maintaining healthy bones and teeth by helping your body absorb calcium. 

But there’s so much more to vitamin D than bone health, it also bolsters your immune system, keeps your muscles working smoothly, and even helps maintain a balanced mood.

You can find vitamin D in certain foods, including:

• Fatty fish
• Egg yolks
• Fortified products such as milk or cereal

Despite these food sources, sunlight remains the primary way most people get their vitamin D. This can make it challenging to maintain optimal levels during darker months or for those who spend much of their time indoors.

Without adequate vitamin D, you may experience a wide-range of problems, including:

• Fatigue
• Muscle weakness
• Bone pain
• Increased risk of fractures

It’s, therefore, essential to maintain healthy levels of this essential nutrient to keep your body healthy and strong. 

While, many people are familiar with vitamin D, what often gets glossed over is that it actually exists in two main forms:

1. Vitamin D2 (ergocalciferol)
2. Vitamin D3 (cholecalciferol)

From their sources to effectiveness, let’s dive into the key differences between them…

Where Do We Get Them From?

At its core, the difference between vitamin D2 and D3 lies in their origins.

Vitamin D2 is primarily plant-based and consequently comes from sources like mushrooms which have been exposed to ultraviolet (UV) light. It’s also the go-to choice for many fortified products, thanks to its lower production cost.

On the other hand, when it comes to food, Vitamin D3 solely derives from animal sources, such as liver, fatty fish, butter and egg yolks.

This key distinction between their sources extends to how they are produced in the body. Vitamin D3 is the only form your body naturally makes. When your skin absorbs UVB rays from sunlight, a chemical reaction converts a compound in your skin, 7-dehydrocholesterol, into vitamin D3. Making sure we spend enough time in the sun is, therefore, the most natural and efficient way for humans to obtain vitamin D. Not such a bad way to keep yourself healthy!

Meanwhile, vitamin D2 cannot be produced by our body. Instead, it’s synthesised by plants and fungi when they’re exposed to UV light, as mentioned earlier.

Which Is Better Quality?

There’s been relentless debate in the scientific world concerning whether vitamin D2 supplements are less stable, and consequently worse quality, than D3.

Indeed, research has shown that vitamin D2 is more sensitive to environmental factors like humidity and temperature fluctuations, which could cause it to degrade faster over time.

This would mean that vitamin D2 supplements lose their potency faster than D3.

However, to date, no studies have directly compared the stability of vitamin D2 and D3 when dissolved in oil, which is common in many supplements.

So, for now, there’s absolutely no need to stress about the quality of your vitamin D2 supplements. As long as you store them in a cool, dry place, in a closed container, and away from direct sunlight, you can ensure they maintain their effectiveness. Until more research comes to light, focus on proper storage, and rest assured that both D2 and D3 can still contribute to your overall vitamin D levels.

Which Is More Effective?

While it’s easy enough to get both forms of vitamin D, the two are actually not equally effective when it comes to raising your vitamin D levels. 

Both vitamin D2 and vitamin D3 are effectively absorbed into the bloodstream, but the liver processes them in slightly different ways.

When you take vitamin D2, your liver converts it into 25-hydroxyvitamin D2. Vitamin D3, on the other hand, is converted into 25-hydroxyvitamin D3. These two forms are collectively known as calcifediol, which is the main circulating form of vitamin D in your body.

However, studies show that vitamin D3 appears to be more effective at raising calcifediol levels in the blood than vitamin D2. In fact, vitamin D2 appears to produce lower levels of calcifediol compared to the same amount of vitamin D3.

So, while both forms are beneficial, vitamin D3 typically delivers better results and should be the one you choose as a staple of your supplement regimen. 

The Bottom Line

Vitamin D is a powerhouse nutrient that keeps your bones strong, your immune system in check and your mood balanced. But with there being two main forms, some confusion can occur as to which is best. 

To put it bluntly, vitamin D3 is the one you should be taking. Indeed, a singular number can make a big difference, with vitamin D3, according to several studies, being more effective at boosting your vitamin D levels than D2. 

So, if you’re struggling to spend enough time basking in the sun or not a big fan of vitamin D-rich foods, stay healthy, energised and ready to take on the day by supplementing with vitamin D3!