Why Vitamin D3 is That Much Better: The Difference Between Vitamin D2 and D3

Vitamin D is one of our most important vitamins for optimal health and functioning. Commonly called the “sunshine vitamin,” it is one of 13 vitamins our bodies can make, but uniquely, the only one that can be made from exposing the skin to sunlight. Vitamin D is popularly thought of as being responsible for skeletal maintenance and bone health, but recent evidence suggests it even plays a role in cellular processes that underly many illnesses like cancer, hypertension, and diabetes.

However, the prevalence of vitamin D deficiency is staggering; over 50% of the population across the world suffers from a clinically significant lack of vitamin D, despite its bioavailability in the sunshine. The evidence is clear; we need more vitamin D in our lives.

But here comes the kicker: vitamin D exists in many forms, the most abundant in our diet being vitamin D3 and vitamin D2. Depending on your goals, one type of vitamin D may be more useful to you than the other. At ATH Organics, we believe that vitamin D can be demystified and that this worldwide deficiency is correctable through a combination of lifestyle adjustments, supplementation, and education. 

Today, we will be dissecting the mystery surrounding vitamin D, and the best ways to compare vitamin D3 and D2. Specifically, let’s talk about:

  • What vitamin D is … 

  • Why Vitamin D is good for you … 

  • How vitamin D3 and vitamin D2 differ...

  • How to increase your daily intake of vitamin D…

Choosing between vitamin D3 and D2 doesn’t have to be such a hassle. There are concrete, significant differences between the two, and we are dedicated to placing the most important information in your hands to better inform your choice. In addition to what we already know, research is revealing the powerful impact this vitamin has on our bodies. 

With this in mind, let’s look at what vitamin D, in all its forms, actually does for your body…


Vitamin D is the sunshine vitamin for a reason; direct skin exposure to the sunlight can make abundant vitamin D. You can ingest vitamin D-rich foods, as well. =

It exists in two different types: vitamin D2 and vitamin D3. 

Vitamin D receptor (VDR) is found throughout the human body, in almost all of our tissues and cells; this is why vitamin D’s fat solubility works well in the body, as it can be stored in fatty tissues for an extended period of time. It facilitates calcium absorption in the body, as well as ensuring dietary phosphorus is properly absorbed into our organs and bones.  

The type of vitamin D we get from our diet and from the sun is biologically inactive, so our bodies need to process it in a systematic way.


  • The vitamin is distributed into chylomicrons, which are just small packs of fat found throughout the bloodstream. 
  • These packs are absorbed into the lymphatic system and then introduced into the blood.
  • The vitamin is processed (i.e hydroxylated) in the liver, then in the kidneys, where it forms its biologically active variant, vitamin D 1,25(OH)2D. 

Vitamin D facilitates crucial bodily and cellular processes like stimulating the production of insulin, inhibiting angiogenesis (the process by which blood vessels form, often implicated in cancerous tumor formation), as well as creating immune cells that fight disease. 


Vitamin D regulates important biological functions across your body. It is involved in stabilizing bones by way of regulating calcium and phosphorus absorption in the gut, which also ensures your teeth remain healthy. In fact, one of the reasons scientists discovered vitamin D and its role in bone health was by examining children who developed rickets; the biological deficiency that caused rickets was unknown until 1928 when scientists found that deficiencies in vitamin D caused rickets in animal models of the disease.

Beyond that, it is involved in most of your body’s systems including your immune system, cardiovascular system, and even your nervous system.

Adequate vitamin D intake has been associated with:

We can also see the benefits of vitamin D3 and D2 when we see the flipside. Specifically, the kind of harm a deficiency in vitamin D can cause on our everyday functioning.

Vitamin D deficiency, also known as VDD, has been associated with many health issues such as:

Maintaining optimal vitamin D levels in the body becomes slightly more complicated when you have different friends, doctors, websites, even coaches championing either vitamin D3 or D2. 

Let’s look at the differences that separate them, and why one is most definitely the better choice...


Vitamin D3, also known as cholecalciferol, differs from other forms of vitamin D by the fact that direct contact with sunlight produces it. The interaction with ultraviolet B radiation from the sun catalyzes the synthesis of vitamin D3 in the skin. It is also found in abundance in animal products such as oily seafood, egg yolks, butter, and dairy. 

Vitamin D2, known chemically as ergocalciferol, is derived from plants. Whereas our skin produces vitamin D3, the skin of fungi and plants produce vitamin D2. Notably, humans do not naturally produce vitamin D2, making vitamin D3 the more bioavailable and natural type.

These compounds are not created equal, and in many cases, vitamin D3 is the better choice. Here’s why:

While it may be tempting and easier to treat both vitamin D3 and D2 as the same thing, it is clear that vitamin D3 confers greater benefits by way of its superior efficacy, metabolism, and shelf life. 


If you come away from this article with just one piece of knowledge, know that vitamin D deficiency is correctable through small adjustments that maximize your intake of D3. The natural route of sun exposure is a good option, but for many of us who suffer from sunlight sensitivity, baking outside for too long every day may not be the best.

That is why ATH Organics is releasing our Vitamin D3, coconut oil, and Bioperine (black pepper):

  • Vitamin D3: while many over-the-counter supplements only have 1000 IU (international units) of D3, ATH Organics’ vitamin D3 capsules contain 5000 IU.

Increasing your daily intake of vitamin D3 can be as easy as taking a capsule daily, in combination with lifestyle adjustments like eating more D3-rich foods. 


Q: Can vitamin D deficiency cause weight gain?

A: The link between obesity and vitamin D deficiency is well-documented, but surprisingly, this relationship is conserved across age, gender, and geographical location. While it is currently unknown exactly how this deficiency leads to weight gain, scientists suggest that lacking vitamin D can cause hormonal changes that promote excessive fat storage. 


A: Toxicity from vitamin D is very rare, and only in individuals who take upwards of 50,000 - 1 million units a day for an extended period of time even approach the danger zone. Subjects who took 2000, 3000, 4000 and 5000 IU  of vitamin D daily showed a systematic increase in vitamin D presence in blood with no adverse effects. This means that vitamin D’s effects are dose-dependent, and greater doses confer larger concentrations in the blood.

If you’re concerned about finding your optimal dose -- or you fear that you suffer from a vitamin deficiency --  your physician can order a full blood panel that will detect vitamin D in your body, and determine the best dosage for your lifestyle, weight, age, and health history.


A:  In a landmark clinical trial conducted by the University of Zurich, Vitamin D3 supplementation in healthy adults significantly improved scores on a self-report questionnaire assessing fatigue in comparison to adults who received a placebo. This suggests that vitamin deficient adults can benefit from D3 supplementation to improve energy levels. 


A: Since vitamin D3 has a remarkable impact on improving fatigue, you should avoid taking it late in the day as it could disrupt your sleep cycle by way of reducing melatonin production, the hormone responsible for regulating sleep. This effect is still not well understood, however. The most important part of supplementing is to be consistent and doing what works best with your schedule. 


The sunshine vitamin has a stellar reputation that is well-earned. Vitamin D is a critical part of achieving and maintaining optimal health across your life, and using the highest quality supplementation available is part of it. ATH Organics delivers quality supplements that improve wellness for all levels of fitness; with vitamin D being so important, we believe everyone deserves the opportunity to get enough and use it to its fullest potential.

Vitamin D3

90 Servings
5000 IU of Vitamin D3
500mg of Coconut Oil to Boost Absorption
5mg of BioPerine to Boost Absorption
Non-GMO, Soy Free & Gluten Free

90 Servings

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