difference between vitamins D and D3

Are Vitamins D and D3 the Same

If you’re unfamiliar with fat-soluble vitamins, you may be curious about the difference between vitamins D and D3. This is especially so if you’re contemplating taking dietary supplements to boost your vitamin D levels. 

Vitamin D is often mistaken for vitamin D2. You’ll not find any supplement labeled as “vitamin D” because pharmacies don’t recognize such. Vitamin D2 and D3 are different because D2 comes from plant sources, while vitamin D3 comes from animal sources.

But this is not all you should know about these vitamins. Understanding their components and how they work will help you know the suitable vitamin options for you. Learning the differences is also essential because the names can be confusing.

This article will take you through the differences between these two vitamins, their health benefits, and all other necessary comparisons you should make. Continue reading to learn more. 

What is Vitamin D?

What is Vitamin D?

There are multiple options in the D vitamins category. All these vitamins are crucial to bone health and calcium absorption. They also contribute to building your immune system to ensure adequate health status. 

The human skin produces vitamin D when it gets enough sun exposure. However, many people avoid sunlight because of potential skin damage and cancer risk. 

While some people stay away from sunlight completely, others use sunscreen to protect their skin. These strategies prevent the skin from producing sufficient vitamin D. 

Additionally, despite the fact that many dairy products contain helpful D vitamins, many people still don’t get enough from these products. 

Consequently, many individuals have inadequate levels of these vitamins, adversely affecting their health. A great solution to consider is using vitamin D supplements.

This vitamin D supplementation comes in two forms: vitamin D2 and vitamin D3 supplements. They are also known as ergocalciferol and cholecalciferol, respectively. 

A notable difference between these two vitamins is that they have different sources. Nonetheless, understanding their key differences helps you know which dietary supplement to choose.

What is Vitamin D3?

Vitamin D3 is a fat-soluble vitamin D supplementation used to help people boost their vitamin levels. If you suffer from vitamin D deficiency, osteomalacia, or rickets, using vitamin D3 according to prescription can help you treat the deficiencies. 

Many people tend to need vitamin D3 supplements. Some of the categories that rely on vitamin D3 are:

  • Breastfed babies
  • Older adults
  • Obese individuals 
  • People with darker skin
  • People with conditions such as Crohn’s disease and cystic fibrosis.

You may take vitamin D3 with other medicine based on prescription. We emphasize the importance of prescription because you must ensure that taking a vitamin D supplement with other drugs is fine for your body. 

For instance, you should avoid vitamin D3 (cholecalciferol) if you have:

  • Too much vitamin D in your body already
  • Allergies to vitamin D
  • Any condition that makes nutrient absorption difficult for your body.

Notably, during the consultation with your doctor, it’s crucial to mention if you’ve had any kidney or heart disease or even electrolyte imbalance. This would inform the doctor’s prescription on how you should use vitamin D3. 

The dosage required for a child or breastfeeding mother differs based on their conditions, age, weight, and diet. Sometimes, the doctor may even ask that you don’t use vitamin D3 at all. 

What are the similarities between vitamin D and D3?

What are the similarities between vitamin D and D3?

Vitamin D and D3 are both meant to boost your health. Although they are supplements, they are both metabolized to provide you with calcitriol accordingly. 

Since calcitriol offers your body an adequate vitamin D level, these two supplement forms serve similar purposes.

Your body increases calcium absorption with adequate calcitriol (the active form of vitamin D). This active vitamin D also helps increase calcium mobilization from bone to plasma. Essentially, vitamin D and D3 offer your body calcitriol, a critical metabolite to your bone and body health.

What’s the difference between vitamin D and Vitamin D3?

There are multiple differences between vitamin D and vitamin D3. A good place to start is to note they have different sources. Even though they help improve your body's vitamin D levels, vitamin D2 comes from plant sources, while D3 comes from animal sources. 

Some of the plant sources producing vitamin D (D2) include fortified foods like cereals and wild mushrooms. Experts measure this vitamin form in international units (IU), with supplements more than 50,000 IU referred to as “prescription only.” 

Other supplements with IU below this threshold are available over the counter. 

Vitamin D2 is costly to produce, as extraction from its sources can be difficult. This is why it’s often contained in fortified foods like milk products. 

On the flip side, sources such as fatty fish, fish oil, egg yolks, and liver produce vitamin D3. 

Your skin is also a major source of vitamin D3 when it receives adequate sun exposure. This is why some refer to vitamin D3 as the “sunshine vitamin.” You can get vitamin D3 over the counter with no exceptions.

Comparison between vitamin D and D3

Vitamin D2

Vitamin D3

Class of drug 

Vitamin D Analog

Vitamin D Analog


You can get both brand and generic supplement options

You can get both brand and generic supplement options

Drug names

Vitamin D2 or Ergocalciferol, Calcidol, Drisdol, Calciferol

Vitamin D3, Cholecalciferol, Decara, D3 Max, Dialyvite

Drug form

Capsules, oral tablets, and oral liquid solution

Capsules, oral tablets, and oral liquid solution

Standard dosage for vitamin D supplementation

Between 1000 IU to 2000 IU daily

Between 1000 IU to 2000 IU daily

Length of treatment

As long as it takes to build the normal vitamin D levels

As long as it takes to build the normal vitamin D levels

Who uses medication

Adults, adolescents, children, infants

Adults, adolescents, children, infants

Where to buy

Available over the counter if you’re not getting more than 50,000 IU

Available over the counter irrespective of the IU

Conditions treated by vitamin D and D3

Doctors often prescribe vitamin D2 to treat hypoparathyroidism and vitamin D deficiency. Vitamin D3 also serves the same purpose. You can get the two supplements over the counter. However, unlike D3, vitamin D2 can be prescribed by doctors, as not all supplements are available over the counter.

The two vitamin supplements are also used to treat hypophosphatemia and resistant rickets. Vitamin D2 serves this purpose in both its prescription and over-the-counter options. 

Nevertheless, it’s essential to note that the over-the-counter formulation hasn’t received FDA approval for its treatment claims.

Therefore, you should contemplate getting 100% natural dietary supplements from experts. This saves you the stress of purchasing off-label products you may be unsure of their effectiveness. 

Cost comparison of vitamin D vs. D3

Before purchasing vitamin D and D3 supplements, it’s helpful to do a cost comparison of the two options so you can make informed decisions. 

Numerous places sell these supplements at varying prices. But you can save money on your purchases when you understand the average price list or how you can even get these supplements for lower prices.

Since Vitamin D2 is available in prescription and over-the-counter form, many Medicare insurance plans will cover your prescriptions. Understandably, over-the-counter purchases are typically not covered by your insurance. Therefore, you must prepare to incur some costs.

On average, prepare to pay about $54 for 12 weeks of D2 therapy and $50 per month for vitamin D3 monthly. Concerning the D2 option, this pay scale is the average cost for a 50,000 IU dose spanning the aforementioned period. But if you can get these drugs based on a doctor’s prescription, you can pay a reduced price.

This can quickly become a huge bill if you have to make purchases over the counter or can’t secure coupons from brands. It may also become heavy on your finances if you’re running on a budget and can’t get these drugs under insurance.

But there are affordable options you can consider to get enough vitamin D in your body. You can get organic vitamin D3 with 10,000 IU for as low as $17. This will help you support your immune system and bone health and boost your mood.

Ultimately, knowing the right place to buy your vitamin D2 and D3 supplement is crucial to saving money on your purchases. Why Not Natural offers affordable 100% vitamins in liquid form so that taking them is more enjoyable.

Drug interactions of vitamin D vs. D3

Although vitamin D and vitamin D3 can be used with many other drugs, you must understand their drug interactions to know the combination to avoid. The two drugs are metabolized to increase calcium levels, so they have similar interactions. 

Using vitamin D alongside aluminum hydroxide may affect the aluminum’s serum levels. This is a combination you should avoid to deter further complications. 

Similarly, using vitamin D with hydrochlorothiazide may increase calcium levels dangerously. Therefore, you should ordinarily avoid this combination too.

But if you must use vitamin D supplements while on thiazide diuretics, you should ensure you do so with the instructions of a healthcare provider. 

Other drugs that may affect vitamin D effectiveness include bile-acid sequestrants and cholestyramine. 

Is vitamin D or D3 more effective?

Knowing which of the two vitamin D options produces more vitamin levels may impact your purchase decision. After all, if you’re highly deficient in vitamins, you’ll want the option that increases your vitamin levels quickly. Vitamin D3 tends to produce more vitamins compared to D2. 

Both vitamins D2 and D3 go into your bloodstream after taking the supplements. The liver metabolizes them into 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3. Collectively, these two options are referred to as calcifediol or 25-D. 

Calcifediol directly reflects your body’s vitamin levels. Therefore, when you undergo a test to assess your vitamin levels, the lab tests your calcifediol levels. When it’s low, you’ll need a prescription for vitamin intake. 

Like you, many people have been curious about the more effective option between vitamin D2 and vitamin D3. According to a study from the National Institutes of Health, vitamin D3 produces more vitamins compared to its D2 counterpart, following a test on vitamin-deficient post-menopausal women. 

Another clinal trial testing for effectiveness also found vitamin D3 offering superior results over vitamin D2

Nevertheless, it’s important to consult a medical practitioner to guide your choices when contemplating which option to choose. You should also inform the health provider about any health conditions you have. 

Full disclosure with your health provider will ensure you receive the best care. Remember that inadequate drug interaction with vitamin D intake may adversely affect its effectiveness. 

How much vitamin D and D3 should I take every day?

The right dose of vitamin D you should take depends on different factors such as age, condition, vitamin D deficiency, and more. Understanding your circumstances will help to inform how much vitamin you should take. On average, you should take between 400-800 IU daily.

The above recommendation is from the National Institutes of Health (NIH). However, you may need to take more than that if you aren’t getting enough sun exposure, have darker tones, or use sunscreen a lot. 

For instance, a study found that people with vitamin D deficiency required 5,000 IU to reach 30 ng/ml blood levels. 

Obese people and post-menopausal women may also need to use higher doses than the average. Post-menopausal women are said to need between 800-2000 IU to improve their vitamin levels to 20 ng/ml.

Nevertheless, the National Institutes of Health has put the safe limit at 4,000 IU. This means that you shouldn’t surpass this limit, irrespective of your vitamin deficiency, without speaking to a healthcare provider. 

Comparison between Vitamin D and D3

Takeaway: You can boost your vitamin levels with the right supplement

Many people worry about their vitamin levels and how to improve them accordingly. You can do this by taking either vitamin D or D3 supplements. These supplements are metabolized to provide you with calcium levels that improve your vitamin levels and support your immune system. 

Focus on understanding your circumstances, such as age and health status, to understand what supplement to use. Ensure you speak with a healthcare practitioner if you have other medical conditions or are unsure about your dose. 

Remember that certain irregular interactions with vitamin D or D3 intake may have unhealthy effects.

You can avoid many issues by going for clean supplements that work. At Why Not Natural, you can get 100% natural supplements available in liquid form. 

These dietary supplements offer you a faster and more convenient vitamin D improvement journey. Given that they are natural supplements, you stay clear of risks that could further complicate your conditions.

Why Not Natural offers you vitamin D, vitamin B12, vitamin A, Zinc, and more in precisely the way your body craves.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.