Vitamin D2 vs. D3: What Is the Difference, and Which Is Better?
By Rosanna Sutherby, PharmD
Vitamin D, also called calciferol, is a fat-soluble vitamin produced by your body when your skin is exposed to sunlight. It is available as a dietary supplement and a prescription medication, and it is naturally present in or added to some foods. Vitamin D2 and D3 are the two primary forms of vitamin D. Although they are often used interchangeably, you may ask, what is the difference between vitamin D2 and vitamin D3?
Vitamin D2 vs. D3: What Is the Difference Between Vitamin D2 and D3?
Vitamin D2 and D3 are slightly different in their chemical structures. However, they are both absorbed well from your small intestine. Vitamin D2 is derived from plant sources, and vitamin D3 comes from animal sources or exposure to sunlight.
Is Vitamin D2 the Same as Vitamin D3?
Vitamin D2 and D3 are slightly different. Both forms raise your blood vitamin D levels, and both can treat and prevent rickets from vitamin D deficiency. However, studies have found that vitamin D3 effectively raises blood vitamin D levels for a longer period than vitamin D2.
Additionally, vitamin D2 and D3 are derived from different sources. Vitamin D2 is plant-based. It is made by exposing ergosterol found in yeast to ultraviolet (UV) light. Vitamin D2 can also be found in some types of mushrooms. Vitamin D3 is sourced from sheep lanolin. It is made by exposing the lanolin to UV radiation to convert the cholesterol in lanolin to vitamin D3.
Vitamin D supplements can contain either vitamin D2 or D3. However, most over-the-counter (OTC) preparations contain vitamin D3.
Cholecalciferol vs. Ergocalciferol: Vitamin D3 vs. D2 Comparison
Cholecalciferol is the scientific word for vitamin D3. Ergocalciferol is the scientific word for vitamin D2. The following is a summary of how they compare in absorption, metabolism, efficacy, and sourcing:
Cholecalciferol and ergocalciferol are absorbed equally well from your small intestine.
Cholecalciferol and ergocalciferol are both metabolized by the liver and kidneys.
Although cholecalciferol and ergocalciferol are absorbed equally well, research shows that cholecalciferol is more effective in raising and maintaining vitamin D levels in your bloodstream.
Cholecalciferol: Cholecalciferol is an animal product made from sheep lanolin. It is also the form of vitamin D that your body makes when your skin is exposed to UV rays in sunlight.
You can obtain cholecalciferol from your diet in sources such as:
- Fish liver oils
- Fortified cereals
- Fortified milk
- Tuna fish
Ergocalciferol: Ergocalciferol is a plant-based product derived from yeast and some mushrooms. Sources of ergocalciferol include:
- Fortified cereals
- Fortified orange juice
- Fortified non-dairy milk (oat, almond, soy)
Why Do Doctors Prescribe Vitamin D2 Instead of D3?
When you get a prescription from your doctor for vitamin D, it is typically for ergocalciferol or vitamin D2. You may wonder why doctors prescribe vitamin D2 instead of D3, if vitamin D3 appears to be more potent than vitamin D2.
The vitamin D prescription you get from your doctor is typically for 50,000 units of vitamin D2. Vitamin D2 is indicated to treat calcium disorders and parathyroid disorders. It is also the preferred form for patients with chronic kidney disease.
Vitamin D2 vs. D3: Which Is better?
When determining which is better between vitamin D2 and D3, consider a few. Based on research, vitamin D3 may be somewhat more potent than vitamin D2. Vitamin D3 is more effective in raising vitamin D levels in your bloodstream for a longer period than vitamin D2.
On the other hand, vitamin D2 is sourced from plants, and vitamin D3 is derived from animals. If you prefer a plant-based product, vitamin D2 is a better choice for you.
Additionally, your doctor may recommend vitamin D2 as the best option for you if you have chronic kidney disease.
Vitamin D3 vs. D2: Final Points
When you shop for an OTC vitamin D supplement, you will likely find vitamin D3 or cholecalciferol. This is the form of vitamin D that your body makes through exposure to UV sunlight. Vitamin D3 is an animal-sourced product. If you are looking for a plant-based supplement, look for vitamin D2 or ergocalciferol. If you have kidney problems, be sure to talk with your provider before taking OTC vitamin D.
Rosanna Sutherby is a freelance medical writer who has been a practicing pharmacist in her community for close to 20 years. She obtained her Doctor of Pharmacy from Nova Southeastern University in Ft. Lauderdale, FL. She utilizes her clinical training in the pharmacy, where she helps patients manage disease states such as asthma, diabetes, heart disease, hypertension, and many others. Dr. Sutherby reviews and recommends drug regimens based on patients’ concurrent conditions and potential drug interactions.