What Is Another Name for Colecalciferol? Exploring Vitamin D3

November 20, 2025 •

2 min read

Over one billion people worldwide are estimated to have a vitamin D deficiency. Knowing what is another name for colecalciferol can help you better understand and identify this essential nutrient, also known as Vitamin D3. This fat-soluble vitamin plays a critical role in numerous bodily functions, including maintaining strong bones and supporting the immune system.

Quick Summary

Colecalciferol is most commonly known as Vitamin D3 and is vital for absorbing calcium and phosphorus for bone health. It is synthesized in the skin from sun exposure and found in certain animal products and supplements. A deficiency can lead to bone diseases like rickets and osteomalacia.

Key Points

Identity: Colecalciferol is another name for Vitamin D3, a fat-soluble vitamin essential for health.
Synthesis: The body produces colecalciferol naturally in the skin when exposed to UVB rays from sunlight.
Function: It is crucial for the absorption of calcium and phosphate, which are necessary for strong bones.
Sources: Besides sun exposure, colecalciferol is found in fatty fish, egg yolks, and fortified foods, and is widely available in dietary supplements.
Deficiency Risk: Individuals with limited sun exposure, dark skin, or certain health conditions are at higher risk for colecalciferol deficiency.
Potency: Vitamin D3 (colecalciferol) is generally more potent and effective at raising and maintaining vitamin D levels than Vitamin D2 (ergocalciferol).

The Identity of Colecalciferol: Vitamin D3

Colecalciferol is often called cholecalciferol or Vitamin D3. This fat-soluble vitamin is made in the body when skin is exposed to UVB rays from sunlight and is also found in some foods and supplements. Vitamin D3 is considered more effective than Vitamin D2 (ergocalciferol) at raising vitamin D levels in people.

How Your Body Synthesizes Colecalciferol

When skin is exposed to UVB radiation, 7-dehydrocholesterol is turned into colecalciferol. The body controls this process to prevent toxic levels from too much sun exposure. Various things like where you live, skin color, age, and sunscreen affect how much is made.

The Importance of Colecalciferol for Health

Colecalciferol is changed in the body to calcitriol, which is important for several functions:

Calcium and Phosphate: Helps the body take in calcium and phosphorus, which are key for healthy bones and teeth.
Bone Health: Helps stop bone problems such as rickets, osteomalacia, and osteoporosis.
Immune System: Supports the immune system to fight off infections.
Other Systems: Studies suggest it may help with heart health, mood, and reducing swelling.

Sources of Colecalciferol

Getting enough colecalciferol often needs more than just sun. Sources include {Link: DrugBank https://go.drugbank.com/drugs/DB00169}:

Fatty Fish: Like salmon, mackerel, and tuna.
Fish Liver Oils: Such as cod liver oil.
Egg Yolks and Cheese: Have smaller amounts.
Fortified Foods: Like milk, cereals, and orange juice.
Supplements: Available in different types.

Colecalciferol vs. Ergocalciferol: A Comparison

Knowing the difference between the two main kinds of vitamin D is helpful:


Feature	Colecalciferol (Vitamin D3)	Ergocalciferol (Vitamin D2)
Origin	Animals and supplements from lanolin or lichen	Plants and fungi exposed to UV radiation
Potency in Humans	Generally more effective	Less potent
Synthesis	Produced in human skin upon UVB exposure	Produced by irradiating ergosterol
Dietary Sources	Fatty fish, egg yolks, fortified foods	Fortified foods, mushrooms, yeast
Commercial Use	Common in OTC supplements and fortified foods	Used in supplements, sometimes in prescription doses

Addressing Colecalciferol Deficiency

Things that increase the chance of deficiency include not getting enough sun, having darker skin, being overweight, being older, and having certain illnesses. A blood test can show if you are deficient. Treatment might mean more sun, changing your diet, or taking supplements. Too much can cause high calcium levels in the blood (hypercalcaemia), leading to symptoms like not wanting to eat, feeling sick, and not being able to go to the bathroom.

Conclusion

Colecalciferol is known as Vitamin D3, a key nutrient for healthy bones and a strong immune system. It's made by the body from sunlight and found in certain foods and supplements. Understanding its role, where to get it, and its other names is important for staying healthy and avoiding deficiencies. If you are worried about your vitamin D levels, talk to a doctor.

For additional information, you can find resources like {Link: DrugBank https://go.drugbank.com/drugs/DB00169}.

Frequently Asked Questions

Colecalciferol and cholecalciferol are two different spellings for the same chemical compound, Vitamin D3. Cholecalciferol is the more common and internationally recognized spelling.

The skin contains a compound called 7-dehydrocholesterol. When UVB radiation from sunlight hits the skin, it converts this compound into previtamin D3, which then converts into colecalciferol.

While foods like fatty fish, egg yolks, and fortified products contain colecalciferol, it can be challenging for some people to get enough solely from their diet, especially those with limited sun exposure.

Signs of a deficiency can include bone diseases such as rickets in children and osteomalacia in adults. Other symptoms may include muscle weakness and fatigue.

Yes, excessive doses of colecalciferol can lead to a condition called hypercalcaemia, where calcium and phosphate build up in the body. Symptoms may include nausea, vomiting, and constipation.

The most accurate way to check your colecalciferol levels is through a blood test administered by a healthcare provider. They can then recommend the appropriate course of action.

Some colecalciferol supplements are sourced from lanolin (sheep's wool), but vegan-friendly Vitamin D3 supplements derived from lichen are also available.