Understanding a Vegan Nutrition Diet: Why Is Vitamin D3 Not Vegan?

October 4, 2025 •

4 min read

The majority of conventional vitamin D3 supplements are derived from animal products, a fact often overlooked by new plant-based eaters. This raises the critical question for those following an ethical diet: Why is vitamin D3 not vegan?.

Quick Summary

Conventional vitamin D3 is extracted from lanolin, a waxy substance in sheep's wool, or fish oil, making it unsuitable for a vegan diet. Vegan alternatives include plant-derived vitamin D2 and lichen-sourced vitamin D3, which offer effective, animal-free options for proper nutrition.

Key Points

Lanolin is the Key: Conventional vitamin D3 (cholecalciferol) is extracted from lanolin, a wax found in sheep's wool, which makes it non-vegan.
Vegan D3 is a New Option: Modern vegan D3 is now available, sourced from lichen or algae, and is chemically identical to the animal-derived form.
Vitamin D2 is Plant-Based: Vitamin D2 (ergocalciferol) comes from UV-exposed yeast or mushrooms and is always vegan.
Check Fortified Foods: Many foods are fortified with vitamin D, but some may use animal-derived D3. Vegans must check the label to confirm the source.
Sunlight is a Vegan Source: The body naturally produces vitamin D3 from sun exposure, but this source can be unreliable depending on geography and time of year.

The Core Issue: The Animal Origin of Conventional Vitamin D3

For a substance to be considered vegan, it must be completely free of animal products or byproducts throughout its sourcing and manufacturing process. The primary reason why is vitamin D3 not vegan is its common origin: lanolin. This is a waxy substance derived from sheep's wool. The wool is sheared from sheep, and the lanolin is extracted and processed to isolate the compound 7-dehydrocholesterol. This compound is then exposed to ultraviolet (UV) light, mimicking how the body naturally produces vitamin D from sunlight, to create cholecalciferol (vitamin D3).

Beyond lanolin, some vitamin D3 is also sourced from fish liver oil, another obvious animal-based source. Unless a supplement explicitly states its vitamin D3 source is plant-based, it is safest for vegans to assume it is derived from one of these animal byproducts. The sourcing methods fundamentally contradict the ethical principles of veganism, which seeks to avoid the use of animals for food, clothing, or other products.

The Difference Between Vitamin D2 and D3

To understand vegan-friendly alternatives, it is important to distinguish between the two main forms of vitamin D available in supplements: D2 and D3.

Vitamin D2 (Ergocalciferol): This form is derived from plant and fungal sources, such as mushrooms or yeast, which are exposed to UV light. Therefore, D2 supplements are almost always vegan. Historically, D2 has been considered less effective at raising blood vitamin D levels than D3, though research on this topic is mixed.
Vitamin D3 (Cholecalciferol): As discussed, this form is typically animal-derived from lanolin or fish oil. However, the development of vegan D3 derived from lichen and algae has provided a true vegan alternative that has been shown to be as effective as animal-based D3.

Many fortified foods in the market are enriched with either D2 or D3. Vegans must be vigilant and check the nutritional labels, as some fortified products, like certain orange juices or plant milks, might use animal-derived D3 unless specified otherwise.

Vegan-Friendly Vitamin D Sources

Vegans have multiple ways to meet their vitamin D needs without relying on animal-derived products. These sources fall into two main categories: diet and supplementation.

Dietary sources of vegan vitamin D

UV-Exposed Mushrooms: Certain mushrooms, especially wild or commercially grown ones exposed to UV light, can provide a good source of vitamin D2. Look for labels indicating they are high in vitamin D.
Fortified Foods: Many plant-based milk alternatives (soy, almond, oat), some breakfast cereals, and certain brands of orange juice are fortified with vitamin D. Always check the ingredient list to ensure it specifies vitamin D2 or a vegan D3 source.

Vegan vitamin D supplements

Lichen-derived D3: This is a game-changer for vegans. Specific types of lichen, a unique organism formed by a symbiotic relationship between fungi and algae, can produce vitamin D3 when exposed to UV light. These supplements are chemically identical to animal-derived D3 but are 100% plant-based and suitable for vegans.
D2 Supplements: Vitamin D2 supplements are widely available and are a reliable vegan option for those who are unable to find or prefer not to use lichen-based D3.

Sun Exposure

Sunlight is the most natural source of vitamin D for everyone, regardless of diet. The body synthesizes cholecalciferol (D3) when skin is exposed to UVB radiation. However, factors like latitude, season, time of day, skin pigmentation, and sunscreen use can limit this production, especially for those living in northern climates. A healthcare professional can help determine if sun exposure alone is sufficient for an individual's needs.

Comparison of Vitamin D Sources


Feature	Conventional Vitamin D3	Vegan Vitamin D3	Vitamin D2	Sunlight
Source	Lanolin (sheep's wool), Fish oil	Lichen, Algae	Yeast, Fungi (e.g., Mushrooms)	Direct exposure to UVB rays
Vegan Status	No	Yes	Yes	Yes (natural process)
Form	Cholecalciferol	Cholecalciferol	Ergocalciferol	Cholecalciferol
Manufacturing	Chemical extraction from lanolin/fish oil and UV irradiation	Extracted from UV-exposed lichen/algae	Extracted from UV-exposed yeast/fungi	Synthesized in human skin
Effectiveness	Highly effective in raising blood levels of vitamin D	Equally effective as animal-based D3	Slightly less potent than D3 in some studies	Highly effective but inconsistent depending on factors

Conclusion: Making Informed Choices on a Vegan Diet

For vegans, understanding the source of vitamin D3 is crucial for maintaining dietary ethics. While the conventional form of cholecalciferol is derived from animals, recent developments in nutritional science have provided reliable, vegan-friendly alternatives. By choosing supplements sourced from lichen or algae, or opting for vitamin D2 from yeast, individuals can effectively support their bone and immune health without compromising their vegan principles. Furthermore, maximizing safe sun exposure and incorporating fortified foods are important dietary strategies. The availability of high-quality vegan D3 means that maintaining a plant-based diet no longer requires a trade-off in nutritional efficacy. For those seeking authoritative information on vitamin D, the NIH Health Professional Fact Sheet is an excellent resource.

Frequently Asked Questions

No, while most traditional vitamin D3 is sourced from lanolin (sheep's wool) or fish oil, there is a vegan version available. This plant-based D3 is derived from lichen or algae.

Vitamin D2 is produced by plants and fungi exposed to UV light, while vitamin D3 is typically produced by animals exposed to sunlight. Vegan D3 from lichen is an exception. Some studies suggest D3 may be slightly more effective at raising blood levels, but D2 is still a reliable option.

Vegans can get vitamin D from sun exposure, fortified foods (checking labels for the source), and supplements. Look for supplements that contain vegan D3 from lichen or algae, or opt for D2, which is always vegan.

Lanolin is a fatty wax secreted by the wool-bearing sheep to waterproof their fleece. In manufacturing, lanolin is extracted from sheared wool and processed to create the chemical precursor to vitamin D3, which is then exposed to UV light.

Yes, some mushrooms, particularly certain varieties like maitake and morel, can produce significant amounts of vitamin D2 when exposed to UV light. Many commercially available mushrooms are now treated this way, so check the label.

You need to carefully read the ingredient list. Unless the product label specifically states that the vitamin D3 is from a plant source like lichen, it is most likely animal-derived. Vitamin D2 is always plant-based.

Yes, vegan D3 derived from lichen or algae is chemically identical to animal-sourced D3 and has been shown to be just as effective at raising and maintaining vitamin D blood levels.