Does Vitamin D Have an Alternate Name? Unpacking the Science of Calciferol

November 22, 2025 •

2 min read

According to the National Institutes of Health, vitamin D is a fat-soluble vitamin essential for bone health and immune function. This critical nutrient has been given a more scientific moniker, leaving many to wonder: does vitamin D have an alternate name?

Quick Summary

Vitamin D is also known by the scientific name calciferol, which encompasses several forms like ergocalciferol (D2) and cholecalciferol (D3).

Key Points

Calciferol is an alternate name for vitamin D: The scientific and generic term for vitamin D is calciferol, which encompasses all its different forms.
Two primary forms exist: The two most important forms for human health are ergocalciferol (D2) and cholecalciferol (D3).
Vitamin D requires activation in the body: Both forms must be hydroxylated in the liver and kidneys to become the active hormone, calcitriol.
Sources vary by form: D2 is sourced from plants and fungi, while D3 is synthesized in the skin from sun exposure or found in animal products.
D3 might be more potent: Some evidence suggests that vitamin D3 is more effective than D2 at raising and sustaining blood levels.
Nicknamed the 'sunshine vitamin': Due to its synthesis via sun exposure, it is also commonly referred to by this moniker.

Yes, Vitamin D's Alternate Name is Calciferol

The scientific and generic name for vitamin D is calciferol. This term refers to a group of fat-soluble compounds that help maintain calcium and phosphorus levels in the body. Calciferol includes the two main forms important for human health: D2 and D3. The discovery of this nutrient, linked to research on rickets, established its importance in nutritional science.

The Two Primary Forms of Calciferol

Vitamin D is a collection of related secosteroids. The two key forms in humans are ergocalciferol (D2) and cholecalciferol (D3). Both are converted in the liver and kidneys to become the active hormone, calcitriol.

Ergocalciferol (Vitamin D2): Found in plants, fungi, and yeast exposed to UV light. It's used to fortify foods and in supplements.
Cholecalciferol (Vitamin D3): Produced in the skin from sun exposure. It's also in fatty fish, fish liver oils, and egg yolks.

While both forms raise vitamin D levels, D3 might be more effective at maintaining them longer. Both are absorbed well and can treat deficiency.

Activation of Vitamin D

Vitamin D from sun, diet, or supplements needs to be activated to work in the body.

Liver: D2 and D3 are converted to 25-hydroxyvitamin D (calcidiol), which is measured in blood tests.
Kidneys: Calcidiol becomes 1,25-dihydroxyvitamin D (calcitriol), the active hormone that acts on various tissues.

The “Sunshine Vitamin” and Other Synonyms

Besides calciferol, vitamin D is known as the "sunshine vitamin" because sun exposure leads to its production in the skin. It can also be obtained from foods and supplements. Specific forms have other names:

D2: Also called Activated Ergosterol.
D3: Sometimes referred to as Calciol.

Comparison Table: Vitamin D2 vs. Vitamin D3

Here's a comparison of the main forms of calciferol.


Feature	Vitamin D2 (Ergocalciferol)	Vitamin D3 (Cholecalciferol)
Primary Source	Plants, yeast, and fungi (UV exposed)	Skin synthesis from sun (humans/animals)
Dietary Sources	Some mushrooms, fortified cereals	Fatty fish, fish oils, egg yolks, fortified milk
Effectiveness	Treats rickets effectively	May raise serum 25(OH)D levels higher and longer
Suitability for Vegans	Can be from vegan sources like yeast	Animal-sourced, but vegan lichen versions exist

Health Impacts of Calciferol

Calciferol is crucial for bone health and many other body functions, including immune system regulation, muscle function, and managing inflammation. Vitamin D receptors in various tissues highlight its broad impact.

Conclusion: The Multifaceted Nature of Vitamin D

The alternate name for vitamin D is calciferol, a term for related compounds including D2 and D3. While "sunshine vitamin" points to a key source, calciferol reflects its chemical nature and role in calcium and phosphorus regulation. Understanding these names clarifies the importance of this essential nutrient.

For more details, visit the National Institutes of Health.

Frequently Asked Questions

The scientific and generic name for vitamin D is calciferol. This name is a collective term that refers to all the forms of vitamin D, including D2 and D3.

Yes, there are two primary types of calciferol relevant to humans: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). D2 is from plants, and D3 is from sun exposure and animal products.

The main difference lies in their source. Vitamin D2 is plant-based, while vitamin D3 is produced in the skin from sun exposure and found in animal-based foods. Both are processed similarly by the body to become active.

Vitamin D gets its nickname because the human body naturally produces a form of it (vitamin D3) in the skin when exposed to ultraviolet B (UVB) rays from the sun.

Calcitriol is the biologically active, hormonal form of vitamin D. After vitamin D (D2 or D3) is processed in the liver and kidneys, it is converted into calcitriol, which helps regulate calcium and phosphorus.

Yes, chemically, calciferol is a secosteroid, a molecule with a steroid-like structure where one of the steroid rings is broken.

For most people, both forms are effective at increasing vitamin D levels and treating deficiency. However, some studies have found that D3 may be more effective at raising and sustaining blood concentrations.