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Cholecalciferol vs. Ergocalciferol: What's the Difference?

Edited by Aimie Carlson || By Janet White || Published on February 29, 2024
Cholecalciferol (Vitamin D3) is synthesized in the skin from sunlight, while ergocalciferol (Vitamin D2) is derived from plant sources or supplements.

Key Differences

Cholecalciferol, also known as Vitamin D3, is produced in human skin in response to sun exposure. Ergocalciferol, or Vitamin D2, is obtained from fungal and plant sources and not synthesized in the human body.
Cholecalciferol is naturally produced when skin is exposed to UVB radiation, playing a critical role in calcium absorption. Ergocalciferol, although also aiding in calcium absorption, is less effective than cholecalciferol in maintaining serum Vitamin D levels.
In supplement form, cholecalciferol is often derived from animal sources, such as fish oil or lanolin. Ergocalciferol supplements, on the other hand, are suitable for vegans as they are derived from yeast and other plants.
Cholecalciferol is known to have a longer shelf life and a more potent effect on increasing and maintaining Vitamin D levels in the blood. Ergocalciferol, while effective, requires higher doses to achieve similar effects as cholecalciferol.
The body metabolizes cholecalciferol into its active form more efficiently compared to ergocalciferol, making it a preferred choice in many clinical scenarios. Ergocalciferol’s efficacy can vary depending on dietary factors and individual metabolism.

Comparison Chart


Synthesized in skin from sunlight
Derived from plant or fungal sources


More potent in raising blood Vitamin D levels
Less potent compared to cholecalciferol

Shelf Life

Longer shelf life
Shorter shelf life compared to Vitamin D3

Suitable for Vegans

Usually derived from animal sources
Derived from plant sources, vegan-friendly

Metabolic Efficiency

More efficiently metabolized to active form
Less efficient metabolism to active form

Recommended Dietary Sources

Fish, liver, egg yolks
Fortified foods, supplements

Role in Calcium Absorption

Essential for calcium and phosphorus absorption
Aids in calcium absorption, but less effectively

Stability in Supplements

More stable in supplements
Less stable compared to Vitamin D3

Sun Exposure Relation

Directly related to sun exposure
Not related to sun exposure

Clinical Preference

Often preferred in medical treatments
Used when D3 is not suitable or available

Cholecalciferol and Ergocalciferol Definitions


Cholecalciferol is synthesized in the skin through sunlight exposure.
Regular sun exposure enables the body to produce sufficient cholecalciferol.


Ergocalciferol is a type of Vitamin D, known as Vitamin D2.
Ergocalciferol supplements are a common recommendation for those lacking sunlight exposure.


Cholecalciferol is a form of Vitamin D, also known as Vitamin D3.
After her doctor's recommendation, she started taking cholecalciferol supplements to improve her bone health.


Ergocalciferol is used to treat Vitamin D deficiencies, especially in vegan individuals.
Ergocalciferol is an effective way to increase Vitamin D levels in people with dietary restrictions.


Cholecalciferol is essential for maintaining healthy bones and teeth.
Children need adequate cholecalciferol for proper growth and development.


Ergocalciferol is derived from plant and fungal sources.
Vegans often rely on ergocalciferol to meet their Vitamin D requirements.


Cholecalciferol is used to prevent and treat Vitamin D deficiencies.
Cholecalciferol capsules are often prescribed to individuals with low Vitamin D levels.


Ergocalciferol also plays a role in bone health by aiding calcium absorption.
Alongside calcium-rich foods, ergocalciferol supplements can help in maintaining bone strength.


Cholecalciferol aids in the absorption of calcium and phosphorus.
For better bone density, cholecalciferol is essential along with a balanced diet.


Ergocalciferol is important for immune system function and overall health.
Regular intake of ergocalciferol can support the body's immune response.


See vitamin D3.


See vitamin D2.


Vitamin D3


Constituent of vitamin D1 and vitamin D2.


Vitamin D2, one of the D vitamins, a group of related substances that prevent rickets.


A fat-soluble vitamin that prevents rickets


Are cholecalciferol supplements suitable for vegans?

Typically, no, as they are often derived from animal sources.

How are cholecalciferol and ergocalciferol different in source?

Cholecalciferol is produced in the skin, ergocalciferol is plant-derived.

Is ergocalciferol vegan-friendly?

Yes, ergocalciferol is suitable for vegans.

What is cholecalciferol?

Cholecalciferol is Vitamin D3, a fat-soluble vitamin produced by the body when exposed to sunlight.

What is ergocalciferol?

Ergocalciferol is Vitamin D2, a form of Vitamin D obtained from plant or fungal sources.

Which is more effective, cholecalciferol or ergocalciferol?

Cholecalciferol is generally more effective in raising and maintaining Vitamin D levels.

How does sun exposure affect cholecalciferol production?

UVB rays from the sun stimulate the production of cholecalciferol in the skin.

What role does cholecalciferol play in bone health?

It aids in calcium and phosphorus absorption, essential for bone health.

Is ergocalciferol effective for bone health?

Yes, but it is generally less effective than cholecalciferol.

Can both cholecalciferol and ergocalciferol be used for deficiencies?

Yes, both are used to treat Vitamin D deficiencies.

Are there side effects to taking ergocalciferol?

Similar to cholecalciferol, overuse can cause toxicity.

How is cholecalciferol metabolized in the body?

It is converted into its active form in the liver and kidneys.

Can cholecalciferol and ergocalciferol be used interchangeably?

They can be, but cholecalciferol is often preferred due to its efficacy.

Do ergocalciferol supplements require sunlight?

No, ergocalciferol does not depend on sunlight for its production.

What dietary sources provide ergocalciferol?

It's found in fortified foods and supplements.

How is ergocalciferol metabolized?

Similarly, it is metabolized in the liver and kidneys.

Are there side effects to taking cholecalciferol?

Overuse can lead to toxicity symptoms like nausea and weakness.

What is the recommended dosage for cholecalciferol?

Dosage varies based on individual needs and medical advice.

What is the recommended dosage for ergocalciferol?

Like cholecalciferol, it depends on individual requirements and medical guidance.

Can cholecalciferol be obtained from diet?

Yes, in foods like fish, liver, and egg yolks.
About Author
Written by
Janet White
Janet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
Edited by
Aimie Carlson
Aimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.

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