What Is the Difference Between Vitamin D and Vitamin D3?

What is the difference between vitamin D and vitamin D3?

Here’s the short answer: Vitamin D is the common name for several fat-soluble secosteroids that are important for human health. On the other hand, vitamin D3 is one form of vitamin D synthesized in humans when exposed to UVB light from sunlight or artificial sources.

We’ll provide the long answer, which is much more shocking, in this article. Now let’s get started. 

What Is Vitamin D?

Vitamin D, often referred to as the “sunshine vitamin,” is a fat-soluble nutrient that plays a crucial role in maintaining optimal health. 

Fat-soluble vitamins are a category of essential nutrients that are absorbed and stored in the body’s fatty tissues and liver. 

Unlike water-soluble vitamins, which need to be consumed regularly as they are not stored in the body and are excreted through urine, fat-soluble vitamins can be stored for longer periods and utilized as needed. 

This characteristic allows the body to maintain a reserve of these nutrients, making it less critical to consume them daily.

However, this also means that excessive intake of fat-soluble vitamins, including D, can lead to a toxic buildup in the body. Such a situation can result in potential health problems.

Furthermore, the sunshine vitamin is unique among its peers. It can be manufactured by our skin during exposure to sunlight, specifically ultraviolet B (UVB) rays. 

Vitamin D exists in two main forms. These are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). D2 is found in plant-based sources and fungi, while D3 is found in animal-based sources and synthesized by the skin.

Some primary functions of vitamin D include: 

  • Regulating calcium and phosphorus levels, which are essential for supporting strong bones and teeth. 
  • Facilitating the absorption of these minerals in the gut and helping maintain their balance in the bloodstream. 
  • immune system regulation
  • cell growth modulation
  • inflammation reduction. 

Recent research suggests that adequate vitamin D levels may also play a role in preventing chronic diseases such as multiple sclerosis and type 1 diabetes.

In addition, during the 2020 pandemic, health workers in America gave COVID-19 patients in the region more vitamin D to strengthen their immune system’s defense against the virus. 

Vitamin D2 vs D3

What is Vitamin D2?

Vitamin D2 is also known as ergocalciferol. It isa type of vitamin D that fungi and yeasts produce when exposed to ultraviolet (UV) light. 


We can get vitamin D2 from various plant-based and fortified food sources. Some of the most common sources of vitamin D2 include:

  • Fortified plant milk: Almond, soy, rice, and oat milk are often fortified with vitamin D2. Consequently, they are good options for vegans and those with lactose intolerance.
  • Fortified breakfast cereals: Many breakfast kinds of cereal are fortified with essential nutrients, including vitamin D2. Check the labels to ensure you are getting the right vitamins.
  • Supplements: Vitamin D2 supplements are available in various forms, including tablets, capsules, and liquids.


  • Bone health: Like vitamin D3, vitamin D2 helps the body absorb calcium and phosphorus, essential for building and maintaining strong bones and teeth.
  • Immune system support: Vitamin D2 has been shown to support the immune system by regulating the production of specific immune cells and cytokines.
  • Mental health: Research has linked low vitamin D levels to depression and other mental health issues. Ensuring adequate intake of vitamin D2 can help maintain a healthy mood.
  • Potential cancer prevention: Some studies have suggested that vitamin D2 may have a role in preventing certain types of cancer, such as breast and prostate cancer. However, more research is needed to establish a definitive link.

What Is Vitamin D3?

Picture yourself lounging on a warm, sunny beach, with the sun’s rays gently warming your skin. 

As you’re soaking up that sunlight, your body is doing something pretty amazing: it’s using those rays to create Vitamin D3. 

When sunlight hits your skin, it triggers a process that converts a substance called 7-dehydrocholesterol into Vitamin D3, also known as cholecalciferol. 

Vitamin D3 performs functions similar to vitamin D2, but the former is obtained from different sources. 


  • Sunlight: When you’re outside on a sunny day, your skin produces vitamin D3 as it’s exposed to ultraviolet B (UVB) rays. Keep in mind that factors like the time of day, your geographical location, and your skin type affect how much vitamin D3 your body can produce.
  • Fish: Fatty fish, like salmon and mackerel, are great options. Picture yourself enjoying a delicious grilled salmon dinner, knowing that you’re also nourishing your body with some much-needed vitamin D3.
  • Egg yolks and cheese: These can also provide small amounts of this nutrient. Imagine a leisurely Sunday brunch with your favorite cheese omelet, providing not only a tasty treat but also a source of vitamin D3.
  • Beef liver: Although not everyone’s cup of tea, beef liver is another source of vitamin D3. If you’re feeling adventurous, try incorporating it into your meals now and then to boost your vitamin D3 intake.
  • Fortified foods: Think of that comforting bowl of cereal or that refreshing glass of milk. Food manufacturers often add vitamin D3 to these products, making it easier for you to get your daily dose without much effort.
  • Vitamin D3 supplements: If you’re concerned about not getting enough vitamin D3 from sunlight or your diet, supplements can be a helpful option. Just be sure to consult with your healthcare professional before adding any new supplements to your routine.
Is Vitamin D2 Better than Vitamin D3?

While both forms of vitamin D play essential roles in maintaining good health, they have some differences. 

Vitamin D3 is more bioavailable and effective than vitamin D2 in raising blood levels of calcifediol, the form of vitamin D that circulates the body. 

However, vitamin D2 is still a valuable nutrient, especially for those who follow a plant-based diet or have limited sun exposure.

What Is the Difference Between Vitamin D and Vitamin D3?

The table below sums up the differences between these vitamins.

FactorVitamin D Vitamin D3 
FormRefers to both forms of vitamin; D2 and D3.The form of vitamin D that’s gotten from sunlight. 
Sources Obtained from sunlight, plant, and animal sources. Not obtainable from plant sources. 
Vitamin D vs Vitamin D3

Please consult with your healthcare professional before implementing any significant vitamin-D-related changes to your diet, lifestyle, or supplement regimen.