What is vitamin D3 manufactured from?: The surprising sources explained

October 26, 2025 •

3 min read

Over one billion people worldwide are estimated to have vitamin D deficiency, making supplements a common necessity. For those considering supplementation, understanding what is vitamin D3 manufactured from is crucial, as its origins vary and can impact dietary choices, especially for vegans and vegetarians.

Quick Summary

Vitamin D3 supplements are derived industrially from sources like lanolin found in sheep's wool or newer vegan options from lichen. The body also naturally produces vitamin D3 upon sun exposure, and it is present in fatty animal foods and fortified products.

Key Points

Lanolin is a primary source: Most vitamin D3 supplements are traditionally made from lanolin, a waxy substance extracted from sheep's wool.
Vegan D3 is available from lichen: A plant-based alternative for vitamin D3 is sourced from lichen, a symbiotic organism containing algae and fungi.
Sunlight is a natural factory: The human body naturally synthesizes vitamin D3 when the skin is exposed to UVB radiation from the sun.
D3 is more effective than D2: Studies indicate that vitamin D3 (cholecalciferol) is more efficient at raising and maintaining blood levels than D2 (ergocalciferol).
Process involves UV irradiation: Both lanolin- and lichen-based industrial methods use UV light exposure to convert a precursor compound into cholecalciferol.
Food is a supplementary source: Naturally occurring food sources include fatty fish and fish liver oil, while many other foods are fortified with vitamin D.

The industrial production of vitamin D3

For industrial manufacturing of vitamin D3 (cholecalciferol), two primary sources are used: lanolin and lichen. These materials contain precursors that, when exposed to ultraviolet (UV) light, mimic the process that happens naturally in the skin.

Lanolin: The traditional animal-based source

The most common method for mass-producing vitamin D3 for supplements relies on lanolin, a waxy substance found in sheep's wool. This process begins when sheep are sheared, and their wool is washed to remove debris and extract the crude lanolin. The lanolin then undergoes a multi-step chemical process:

The crude lanolin is refined to extract cholesterol.
This cholesterol is converted into 7-dehydrocholesterol (7-DHC), a precursor also present in human skin.
The 7-DHC is irradiated with UV light, breaking a bond in the molecule to form pre-vitamin D3.
This pre-vitamin D3 is then heat-treated (thermally isomerized) to become vitamin D3 (cholecalciferol).
Final purification steps remove any unwanted isomers formed during irradiation.

Lichen: The modern vegan alternative

For individuals following a vegan lifestyle, an alternative plant-based source of vitamin D3 is now available from lichens. Lichens are composite organisms consisting of a symbiotic relationship between a fungus and an alga or cyanobacteria. The alga or cyanobacteria component can produce cholecalciferol when exposed to UV light.

The process for manufacturing vegan D3 from lichen is as follows:

Specific species of lichen are cultivated and harvested from designated areas.
An oily extract rich in vitamin D3 is extracted from the lichen using methods like water and plant ethanol under pressure.
The extracted oil is then purified and concentrated to meet the potency standards for supplements.

Natural synthesis in the human body

In addition to supplements, the body manufactures its own vitamin D3. This occurs when the skin is directly exposed to sunlight containing ultraviolet B (UVB) radiation. A cholesterol derivative in the skin, 7-dehydrocholesterol, absorbs the UVB energy, which triggers a chemical reaction that converts it first into pre-vitamin D3 and then, through a temperature-dependent process, into vitamin D3. Factors like skin pigmentation, latitude, season, and sunscreen use can all affect the efficiency of this natural production.

Food sources of vitamin D3

While sunlight is a primary source, some foods naturally contain or are fortified with vitamin D3.

Natural food sources of D3:

Fatty fish such as salmon, mackerel, and sardines
Cod liver oil
Smaller amounts are found in egg yolks, cheese, and beef liver

Fortified foods:

Many types of milk (both dairy and plant-based), cereals, and orange juices are fortified with vitamin D to help boost intake.

Comparison of vitamin D sources


Feature	Lanolin-Derived D3	Lichen-Derived D3	Natural Synthesis (Sun)	Animal Food Sources	Fortified Foods
Source	Sheep's wool grease	Lichen (symbiotic organism)	UVB exposure on skin	Fatty fish, eggs, liver	Dairy, cereals, juices
Vegan	No (animal-derived)	Yes (plant-based)	Yes	No (animal-derived)	Variable (check label)
Primary Use	Most common supplement D3	Vegan supplement D3	Primary natural source	Supplementing dietary intake	Boosting intake via diet
Considerations	Not suitable for vegans/vegetarians	A newer, less common source	Can be limited by location, season	Varies by food type and quantity	Depends on product availability

Is vitamin D2 different from vitamin D3?

Vitamin D comes in two major forms: D2 (ergocalciferol) and D3 (cholecalciferol). The key difference lies in their source and metabolic efficiency. D2 is produced by plants and fungi when exposed to UV light, while D3 is produced by animals. Research suggests that vitamin D3 is more effective than D2 at raising and maintaining vitamin D levels in the blood. This is because the body may metabolize the two forms differently, with D3 possibly yielding more of the active form, calcifediol.

Conclusion

Understanding what is vitamin D3 manufactured from is key to making informed dietary choices. For a significant portion of the population that relies on supplements due to limited sun exposure, the primary sources are either lanolin, a byproduct of sheep's wool, or lichen, a plant-based alternative. While the body can synthesize its own D3 with sufficient sunlight, supplements and fortified foods play a vital role in preventing deficiency. As the demand for vegan and sustainably sourced products grows, lichen-derived D3 represents an important advancement in nutritional science, offering a viable and effective option for a wider audience.

Learn more about the latest research on vitamin D metabolism from reputable sources like the National Institutes of Health (NIH) at ncbi.nlm.nih.gov/books/NBK278935/.

Frequently Asked Questions

Lanolin is a waxy, fatty substance naturally produced by sheep's skin to condition their wool. It contains a cholesterol derivative that can be chemically converted into vitamin D3 through UV irradiation, making it a common and traditional source for supplements.

No, not always. While many conventional vitamin D3 supplements are animal-derived from lanolin or fish oil, vegan alternatives are available that are made from plant-based sources, such as lichen.

The main difference is their origin and efficacy. Vitamin D3 (cholecalciferol) comes from animal sources or lichen, while D2 (ergocalciferol) comes from plants and fungi. Studies suggest that D3 is more effective at increasing blood vitamin D levels than D2.

Lichen-derived vitamin D3 is produced by extracting an oily substance from certain species of lichen, a composite organism of fungi and algae. This extract is then purified to create the cholecalciferol suitable for vegan supplements.

It is challenging to get enough vitamin D3 from diet alone, as only a limited number of foods naturally contain it in sufficient quantities. Many people rely on sun exposure, fortified foods, or supplements to meet their needs.

When the skin is exposed to UVB radiation from sunlight, it converts a compound called 7-dehydrocholesterol into pre-vitamin D3. This precursor is then thermally isomerized into active vitamin D3.

Yes, lichen-derived vegan D3 (Vitashine™) is a genuine source of cholecalciferol and is considered just as effective as animal-derived D3 at raising blood vitamin D levels.