Vitamin D is a fat-soluble nutrient essential for the body’s overall function. It enhances the absorption of calcium, supporting the formation and maintenance of strong bones. This compound also acts as an immunomodulator, helping to regulate immune responses. The vitamin is unique because the body can produce it when the skin is exposed to ultraviolet B (UVB) light from the sun. Since reliance on sun exposure is often impractical, dietary sources and supplements are necessary for many people. This creates a complication for vegans, as the most common commercial sources of supplemental Vitamin D are derived from animal products.
The Non-Vegan Origin of Common Vitamin D3
The supplemental form of Vitamin D most frequently recommended is cholecalciferol, also known as Vitamin D3. The standard production method for commercial D3 supplements relies heavily on an animal-derived source. The vast majority of conventional Vitamin D3 is synthesized from lanolin, a wax-like substance harvested from sheep’s wool. During processing, lanolin is extracted, and a precursor compound is isolated and exposed to UV light, converting it into D3.
Since lanolin is a product of sheep husbandry, supplements derived this way are considered animal products and are not suitable for a vegan lifestyle. Consumers must be aware that if a product contains D3 and does not explicitly state a vegan source, it is highly likely to be lanolin-derived.
Identifying Vegan Forms of Vitamin D
For those adhering to a vegan diet, two distinct supplemental forms of Vitamin D are available. The first, and historically more common, is Vitamin D2, known chemically as ergocalciferol. This form is inherently vegan because it is produced by exposing yeast or fungi, such as mushrooms, to ultraviolet light.
The second option is a plant-sourced form of Vitamin D3, extracted from lichen—a symbiotic organism combining algae and fungus. Lichen-derived D3 is chemically identical to the non-vegan, lanolin-sourced D3, but it bypasses the use of animal products entirely.
The choice between D2 and lichen-D3 often comes down to efficacy. D3 is generally considered superior at raising and maintaining active Vitamin D levels in the blood, with studies suggesting cholecalciferol (D3) may be approximately 87% more potent than ergocalciferol (D2). The newer lichen-derived D3 provides vegans access to the more potent cholecalciferol form without compromising their dietary principles.
Maximizing Vitamin D Intake on a Vegan Diet
While supplements are effective, several practical strategies can help increase Vitamin D intake through diet and lifestyle. The most natural way to acquire Vitamin D is through controlled exposure to sunlight, as the body synthesizes cholecalciferol from UVB rays. However, geographic latitude, season, and the use of sunscreen significantly limit this production.
A number of vegan food products are commonly fortified with the vitamin, including plant-based milks, cereals, and orange juices. Consumers must check the ingredient label carefully to confirm the fortification type, as some products may still use the non-vegan D3.
Mushrooms are one of the few natural vegan food sources that provide significant amounts of the vitamin. When exposed to ultraviolet light, mushrooms synthesize ergocalciferol (D2). Certain commercially grown mushrooms are deliberately treated with UV light to boost their D2 content.