You may think Vitamin D is just a single vitamin. However, it’s actually a group of fat-soluble nutrients. The most important compounds are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Before we look at the differences between Vit D2 and Vit D3, it’s essential to learn what Vitamin D is.

What Is Vitamin D?

You may know Vit D as the ‘sunshine vitamin’ – and for a good reason. One source of Vitamin D is sunlight: your skin produces it when exposed to the sun. So for those of us who spend a lot of time indoors or live further away from the equator, food sources of Vitamin D are essential to top up our intake. 

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Dietary sources include red meat, oily fish and egg yolks. It is common for vegans and vegetarians to become deficient in Vitamin D. In fact, even meat-eaters frequently develop a Vitamin D deficiency. For this reason, many opt for food products like cereals fortified with Vitamin D or use supplements to get their intake. 

Read more: Surprising Clues That You May Have A Vitamin Deficiency 

One role of Vitamin D is to help the body absorb calcium, which promotes bone mineralisation and bone growth. Without enough Vitamin D, bones can become brittle or misshapen. 

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Vitamin D benefits also includes supporting the immune system, helps control inflammation and is involved in cell growth and glucose metabolism. There are severe risks of Vitamin D deficiency. A lack of Vitamin D has been associated with various cancers, depression and weight gain.

Vitamin D3 from Animals, Vitamin D2 from Plants

Now we know why Vitamin D is important, let’s talk about the difference between D3 and D2. These two forms are derived from different food sources. Meat products are the primary source of D3, while D2 is found mainly in plant-based sources.

Vitamin D3 Sources

  • Liver
  • Oily fish
  • Butter
  • Egg yolk
  • Dietary supplements

Vitamin D2 Sources

  • Mushrooms that are grown in UV light
  • Fortified foods
  • Dietary supplements

Vitamin D2 is cheaper than D3, so it’s the most common form used in fortified foods.

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Although Vit D3 is mainly found in animal-based sources, our products use 100% natural, vegan D3 from algae.

Vitamin D3 Is Made in The Skin

The Vitamin D made by your skin is the D3 form. Ultraviolet B (UVB) radiation triggers its formation when the skin is exposed to sunlight. So if you’re often outdoors and not wearing sunscreen or heavy clothing, it’s possible to get all your Vitamin D intake from sunshine. 

However, this is not always possible in countries far from the equator or those in high latitude areas. For example, people living in India can get their recommended Vitamin D intake from one hour of midday sun per week. 

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Conversely, those living in the UK will find it challenging to get all their Vitamin D – especially in the winter months. Working and spending most of your time indoors also prevents getting enough Vitamin D from sun exposure.

It can also be dangerous to spend long hours in the sun without adequate sunscreen protection, especially for lighter skin that burns quickly. Overexposure to UV light increases the risk of skin cancer.

To make up for the lack of Vitamin D from UVB radiation, consider increasing your intake of dietary Vitamin D or using supplements.

Shop now: Natural Bone and Joint Health  Supplements with 100% Natural  Real Food Ingredients

Vitamin D3 Is Better at Improving Vitamin D Levels

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Although both Vitamin D2 and D3 are absorbed into the bloodstream, the liver does not metabolise them in the same way. Research suggests that Vitamin D3 is more effective than Vitamin D2 at raising the levels of Vitamin D in the bloodstream.

One small study showed that a single Vitamin D3 dose was almost doubly effective at increasing Vitamin D levels compared to D2. 

Therefore, if you’re considering Vitamin D supplements, it may be advisable to select a product that contains D3 rather than D2.

Read more: Taking Vitamin K with Vitamin D: What’s The Big Deal?

Vitamin D2 Supplements Might Be Lower Quality

Evidence suggests that supplements containing Vitamin D2 could be of lower quality than those containing D3. 

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Studies show that D2 is more vulnerable to humidity levels and temperature changes, making it more likely to degrade over time. Therefore, a supplement containing D3 may be a better option to ensure longevity and effectiveness.

Keeping your supplements in a high-quality, closed and dry container in a dark and room temperature place is the best way to store supplements.


Vitamin D is not a single nutrient. Instead, it is an umbrella term for closely-related compounds – with the most common forms being D2 and D3.

D3 is found in animal sources and produced by the skin, while D2 is derived from plants.

Significantly, Vitamin D3 seems better at increasing your Vitamin D levels. Maintaining a sufficient intake is essential for your health, so including lots of foods with high Vitamin D content and getting lots of (safe) sunshine is a good idea. 

Given the difficulty of getting enough Vitamin D for many people in the UK, we recommend a natural supplement containing Vitamin D3, such as Bone Health Goals.

Medical disclaimer

You must not rely on the information on this blog as an alternative to medical advice from your doctor or therapist. If you have any specific concerns about your mental or physical health, you should consult your doctor and you should not delay seeking medical advice, or treatment for your mental health, because of the information on this blog.