Lichen Vitamin D3: The Vegan Source of D3, How It Compares With D2, and What Vitamin D Can and Cannot Do

For decades, people choosing vitamin D supplements faced a dilemma if they avoided animal products. Vitamin D3 (cholecalciferol), the form the body makes in sunlight, was produced almost entirely from lanolin, a fat extracted from sheep’s wool. Vitamin D2 (ergocalciferol), made by irradiating yeast or fungi, was the vegan option, but research suggests it is less effective at raising blood levels. Lichen, a symbiotic organism of fungi and algae, offered a solution: it naturally contains vitamin D3, and lichen-derived D3 is now sold as a vegan supplement.

Lichen D3 is sometimes described as a remarkable superfood, but it is simply a plant-based source of the same vitamin D3 molecule found in other supplements. This article explains what lichen is, the evidence on vitamin D3 versus D2, who may need supplements, what vitamin D can and cannot do according to major trials, and how to choose and dose vitamin D safely.

What Is Lichen?

Lichens are composite organisms formed by a partnership between a fungus and a photosynthetic partner, usually green algae or cyanobacteria. The fungus provides structure and protection, while the algae or cyanobacteria produce food through photosynthesis. Lichens grow on rocks, trees, soil, and buildings worldwide, from deserts to the Arctic, and some species, such as reindeer lichen, form extensive mats in northern regions. Lichens grow slowly and are sensitive to air pollution, which makes them useful environmental indicators. Some lichens have been used as food in times of scarcity, as dyes, and in traditional medicine.

Lichens produce compounds that help them survive harsh conditions, including intense ultraviolet light. A 2001 study in the Journal of Photochemistry and Photobiology B by Tao Wang, Lars Olof Björn, and colleagues in Sweden identified provitamin D2, vitamin D2, and vitamin D3 in the reindeer lichen Cladina arbuscula. Vitamin D3 content ranged from 0.67 to 2.04 micrograms per gram of dry matter in specimens grown under different natural conditions, and the researchers explored whether levels correlated with UV exposure across latitudes. This natural vitamin D3 content made lichens a candidate source for vegan D3 supplements.

How Lichen Vitamin D3 Supplements Are Made

Commercial lichen D3 is produced by harvesting or cultivating specific lichen species, extracting vitamin D3 and related compounds, and purifying the extract. Because lichens grow slowly, sustainable sourcing is an important consideration, and some producers use cultivated or carefully managed harvests. The resulting cholecalciferol is chemically identical to vitamin D3 from lanolin or fish oil. Lichen D3 products are typically certified vegan and are often combined with plant oils to aid absorption. Because the molecule is the same, lichen D3 should work the same way in the body as other D3 sources; the main differences are ethical and dietary preferences, cost, and product quality.

Vitamin D3 Versus D2

Both vitamin D2 and D3 are converted in the liver to 25-hydroxyvitamin D, the form measured in blood tests, and then in the kidneys and other tissues to the active hormone. Whether the two forms are equally effective has been debated. A 2012 systematic review and meta-analysis in the American Journal of Clinical Nutrition by Laura Tripkovic and colleagues at the University of Surrey pooled randomized trials that directly compared the two and concluded that vitamin D3 was more effective at raising serum 25-hydroxyvitamin D concentrations than D2. The advantage was clearest with large bolus doses and was not significant when the analysis was limited to daily dosing, so the authors called for more research.

A 2017 randomized trial in the same journal by Tripkovic and colleagues then tested daily doses of 15 micrograms (600 IU) of vitamin D2 or D3, given in fortified juice or biscuits, to South Asian and white European women during winter. Women receiving vitamin D3 had significantly greater increases in total 25-hydroxyvitamin D than those receiving D2, by about 15 to 17 nmol/L, and the D3 groups gained about 42 nmol/L more than the placebo group. This supports vitamin D3 as the preferred form, which is why vegans often seek lichen-derived D3 rather than D2.

Who Is Low in Vitamin D?

Vitamin D deficiency is common. A 2011 analysis in Nutrition Research by Kimberly Forrest and William Stuhldreher of 4,495 adults in the 2005–2006 National Health and Nutrition Examination Survey found that 41.6 percent had 25-hydroxyvitamin D levels at or below 20 ng/mL (50 nmol/L), with especially high rates among Black and Hispanic adults. Being obese, not drinking milk daily, and poorer health were also associated with deficiency. People with darker skin, older adults, people who spend little time outdoors or cover their skin, those living at higher latitudes, people with obesity, and those with conditions affecting fat absorption are at higher risk.

Diet matters too, especially for people who avoid animal foods. A 2011 analysis of the EPIC-Oxford cohort in Public Health Nutrition by Francesca Crowe and colleagues measured blood levels in 2,107 British adults and found that vegans had the lowest dietary vitamin D intake and the lowest blood levels, about 56 nmol/L compared with about 77 nmol/L in meat eaters. The difference was larger in winter than in summer, reflecting the importance of sunlight. These findings suggest vegans in particular may benefit from fortified foods or supplements, especially in winter.

Other Sources of Vitamin D

The main natural source of vitamin D is sunlight: ultraviolet B rays convert a cholesterol precursor in the skin into vitamin D3. How much is made depends on season, latitude, time of day, skin pigmentation, age, sunscreen use, and clothing. In much of the United States, Canada, and Europe, winter sunlight is too weak for meaningful production. Few foods naturally contain much vitamin D: fatty fish such as salmon, trout, and sardines, cod liver oil, and egg yolks contain vitamin D3, while fortified milk, plant milks, orange juice, and cereals supply much of the vitamin D in Western diets.

Mushrooms are the main non-animal whole food source. A 2018 review in Nutrients by Glenn Cardwell and colleagues explained that when commonly eaten mushrooms are exposed to ultraviolet light, from the sun or UV lamps, they generate nutritionally relevant amounts of vitamin D, mostly in the D2 form, with smaller amounts of D3 and D4. Levels in UV-exposed mushrooms typically remain above 10 micrograms per 100 grams if eaten before their best-before date, even after some losses from storage and cooking. UV-treated mushrooms and lichen D3 supplements together give people avoiding animal products several options.

What Vitamin D Supplements Can and Cannot Do

Vitamin D is essential for calcium absorption and bone health, and severe deficiency causes rickets in children and osteomalacia in adults. Observational studies linked low vitamin D to many conditions, including cancer, heart disease, diabetes, and depression, raising hopes that supplements could prevent them. Large randomized trials have tempered those hopes. The VITAL trial, published in 2019 in the New England Journal of Medicine by JoAnn Manson and colleagues, randomly assigned 25,871 U.S. men aged 50 and older and women aged 55 and older to 2,000 IU of vitamin D3 daily or placebo for a median of 5.3 years. Vitamin D did not lower the incidence of invasive cancer or major cardiovascular events compared with placebo, and no excess risks of high calcium or other adverse events were found. Most participants were not deficient at baseline, so the results apply mainly to people with adequate vitamin D. Secondary analyses suggested possible benefits for cancer death, which require confirmation.

The lesson is that vitamin D supplements are most clearly useful for correcting or preventing deficiency, supporting bone health in people at risk, and meeting needs when sun exposure and diet are inadequate. They are not a cure-all for people who already have adequate levels.

How Much Vitamin D Do You Need?

According to the NIH Office of Dietary Supplements, the Recommended Dietary Allowance for vitamin D is 600 IU (15 micrograms) per day for people aged 1 to 70, 800 IU (20 micrograms) for adults over 70, and 400 IU for infants. The Tolerable Upper Intake Level for adults is 4,000 IU (100 micrograms) per day. Many experts consider blood levels of 25-hydroxyvitamin D of at least 20 ng/mL (50 nmol/L) adequate for bone health in most people, while some recommend higher targets for certain groups. People with diagnosed deficiency may be prescribed higher doses for a period under medical supervision.

Vitamin D toxicity is rare and almost always results from taking very high doses of supplements for prolonged periods, causing high blood calcium, nausea, weakness, kidney problems, and heart rhythm abnormalities. Sun exposure does not cause vitamin D toxicity because the skin limits production. Vitamin D can interact with certain medications, including some steroids, weight-loss drugs, and anticonvulsants, so people taking medications should consult a clinician.

Supplement form	Source	Vegan?	Notes
Vitamin D3 (lanolin)	Sheep’s wool fat	No (vegetarian-friendly)	Most common and inexpensive D3
Vitamin D3 (lichen)	Lichen extract	Yes	Same molecule; usually costs more
Vitamin D3 (fish oil)	Fish liver oil	No	Cod liver oil also contains vitamin A
Vitamin D2	Irradiated yeast or fungi	Yes	Less effective at raising levels in some studies
UV mushrooms (food)	Mushrooms exposed to UV	Yes	Mainly D2; varies by product

Choosing a Lichen D3 Supplement

Because dietary supplements are not approved by the FDA before sale, quality varies. Look for products verified by third-party programs such as USP, NSF, or similar organizations, which test that products contain what labels state. Check the dose: many lichen D3 products provide 1,000 to 2,500 IU per serving, and some provide more; higher doses are not necessarily better. Vitamin D is fat-soluble, so taking it with a meal containing fat improves absorption, and many products are dissolved in plant oils. Vegan certification confirms the absence of animal-derived ingredients, including capsule materials such as gelatin. Some products combine vitamin D3 with vitamin K2; evidence for added benefit from this combination in healthy people is limited.

Should You Test Your Vitamin D Level?

Routine screening of healthy adults is not universally recommended, and the U.S. Preventive Services Task Force has found insufficient evidence for screening people without symptoms. Testing may be appropriate for people at high risk of deficiency, such as those with osteoporosis, malabsorption conditions, limited sun exposure, darker skin living at high latitudes, or vegans not taking supplements, and for people with symptoms such as bone pain or muscle weakness. A clinician can interpret results and recommend appropriate doses.

Lichens Beyond Vitamin D

Lichens have attracted research interest for other compounds as well. Usnic acid, found in Usnea and some other lichens, has antimicrobial properties and has been used in topical products, but oral usnic acid supplements marketed for weight loss were linked to serious liver toxicity, prompting FDA warnings in the early 2000s. Iceland moss, a lichen used traditionally for coughs and sore throats, appears in some lozenges. These examples show that lichens contain biologically active compounds that can be both useful and harmful, and that whole lichen products should not be assumed safe simply because they are natural. Purified lichen D3 supplements are different: they deliver a well-characterized vitamin at a measured dose.

Sustainability and Sourcing

Lichens grow slowly, sometimes only a few millimeters per year, and wild populations can take decades to recover after harvesting. Reindeer lichen is an important winter food for caribou and reindeer in Arctic regions. Responsible producers of lichen D3 address these concerns through sustainable harvesting practices, cultivation, or limiting harvest volumes, and some publish information about their sourcing. Consumers who care about sustainability can look for brands that explain where and how their lichen is obtained.

Vitamin D for Vegans and Vegetarians

Because few plant foods contain vitamin D, vegans depend mainly on sunlight, fortified foods, UV-exposed mushrooms, and supplements. In regions with long winters, many health organizations suggest that vegans consider supplementation during darker months. Fortified plant milks often use vitamin D2, though some use D3 from lichen; checking labels helps. Vegetarians who eat eggs and dairy obtain some vitamin D from those foods, but intake is still usually below recommendations without fortification or supplements. Planning for vitamin D, along with vitamin B12, iodine, and omega-3 fats, helps people following plant-based diets meet nutritional needs.

Vitamin D and Bone Health

The strongest evidence for vitamin D relates to bones. Adequate vitamin D allows efficient calcium absorption, and deficiency can lead to soft bones, bone pain, and fractures. In older adults at risk of falls and fractures, guidance generally emphasizes adequate vitamin D and calcium from diet and supplements as needed, combined with exercise and fall prevention, though trials of vitamin D alone for preventing fractures in people who are not deficient have produced mixed results. People with osteoporosis should follow their clinician’s guidance on vitamin D, which is often part of treatment plans.

Vitamin D in Pregnancy, Infants, and Children

Vitamin D needs during pregnancy and breastfeeding are the same as for other adults under U.S. guidelines, 600 IU daily, though some clinicians recommend testing and supplementation for people at higher risk of deficiency. Breast milk contains relatively little vitamin D, so the American Academy of Pediatrics recommends that breastfed and partially breastfed infants receive 400 IU of vitamin D daily starting soon after birth. Infant formula is fortified. Children and teenagers who drink little fortified milk, spend limited time outdoors, or follow vegan diets may need supplements. Parents choosing vegan supplements for children can use lichen D3 products formulated for children, at doses recommended by their pediatrician.

Vitamin D and Immune Health

Vitamin D receptors are found on immune cells, and vitamin D influences immune responses. Some trials have suggested that daily or weekly vitamin D supplementation may modestly reduce the risk of acute respiratory infections, particularly in people who are deficient, while bolus doses given infrequently appear less effective. Results have been inconsistent, and vitamin D is not a substitute for vaccination or other proven preventive measures. Maintaining adequate vitamin D is reasonable for overall health, but expectations for immune benefits should be modest.

A Balanced View

Lichen vitamin D3 is a genuine innovation for people who avoid animal products, providing the more effective D3 form without lanolin or fish oil. It is not a superfood with special powers, and vitamin D supplements in general have shown limited benefits for preventing chronic disease in people who are not deficient. The most sensible approach is to identify whether you are at risk of deficiency, use sunlight and fortified foods wisely, and supplement at recommended doses when needed, choosing lichen D3 if you prefer a vegan product.

Practical Takeaways

If you are vegan, have darker skin, live at a high latitude, are older, or spend little time outdoors, consider whether you need vitamin D supplements, especially in winter. Choose D3 over D2 when possible; lichen D3 provides a vegan option. Take vitamin D with a meal containing fat. Stay within recommended doses unless a clinician advises otherwise, and do not exceed 4,000 IU daily without medical supervision. Look for third-party tested products. Ask your clinician about testing if you have risk factors or symptoms.

How Vitamin D Works in the Body

Whether it comes from sunlight, food, or supplements, vitamin D is biologically inactive until it undergoes two conversions. The liver converts it to 25-hydroxyvitamin D, the main storage and circulating form, which has a half-life of a few weeks. The kidneys and other tissues then convert it to 1,25-dihydroxyvitamin D, the active hormone that regulates calcium and phosphate absorption in the gut and influences bone remodeling. Many tissues, including immune cells, muscle, and the brain, have vitamin D receptors, which is why researchers have explored effects beyond bone. Because 25-hydroxyvitamin D reflects intake and sun exposure over weeks, it is the best blood marker of vitamin D status.

Signs of Vitamin D Deficiency

Mild deficiency often causes no obvious symptoms. More severe or prolonged deficiency can cause bone pain, muscle weakness or aches, fatigue, and, in children, rickets with bowed legs and delayed growth. In adults, deficiency contributes to osteomalacia and can worsen osteoporosis, increasing fracture risk. Because symptoms are nonspecific, people at risk should discuss testing rather than self-diagnosing.

Questions to Ask Your Clinician

Am I at risk of vitamin D deficiency based on my diet, skin type, location, health conditions, or medications? Should I have my vitamin D level checked? What dose of vitamin D3 is appropriate for me, and for how long? Is a vegan lichen D3 product suitable for my needs? Do any of my medications interact with vitamin D? Should I also consider calcium for bone health? These questions help tailor supplementation to individual needs rather than relying on general marketing claims.

Reading Vitamin D Labels

Supplement labels list vitamin D in international units (IU), micrograms (mcg), or both; 1 microgram equals 40 IU. Labels should state whether the product contains cholecalciferol (D3) or ergocalciferol (D2), and vegan D3 products usually specify the lichen source. Check serving size, since some products require two capsules per dose. Fortified foods list vitamin D on the Nutrition Facts panel as micrograms and percent Daily Value, with the Daily Value for adults set at 20 micrograms (800 IU). Comparing labels helps avoid accidentally exceeding upper limits when combining fortified foods and supplements.

Vitamin D and Older Adults

Aging skin produces less vitamin D, and older adults often spend more time indoors, increasing deficiency risk. Kidney function changes can also affect activation. For these reasons, recommended intake rises to 800 IU after age 70. Older adults taking multiple medications should review vitamin D and calcium supplements with their clinicians to avoid interactions and excessive calcium intake. Regular weight-bearing exercise, adequate protein, and fall prevention measures complement vitamin D in protecting bone health and independence as people age, and vegan older adults may especially benefit from planning for both vitamin D and calcium.

Common Myths

“Lichen vitamin D3 is superior to other D3.” It is the same molecule; the difference is source and suitability for vegans.

“More vitamin D is always better.” Large trials found no benefit for cancer or heart disease in people with adequate levels, and very high doses can be harmful.

“You can get enough vitamin D from food alone.” Few foods are rich in vitamin D, so most people rely on sunlight, fortified foods, or supplements.

“Sunscreen makes vitamin D production impossible.” Sunscreen reduces production, but most people still make some vitamin D; skin cancer prevention remains important.

“Vitamin D2 is useless.” D2 raises vitamin D levels, though D3 appears more effective in several studies.

Key Terms

Cholecalciferol: Vitamin D3, made in skin and found in animal foods, lanolin, and lichen.

Ergocalciferol: Vitamin D2, made by irradiating yeast and fungi.

25-hydroxyvitamin D: The main circulating form of vitamin D measured in blood tests.

Lichen: A symbiotic organism formed by a fungus and algae or cyanobacteria.

Lanolin: A fat from sheep’s wool used to make most vitamin D3 supplements.

The Bottom Line

Lichens naturally contain vitamin D3, and lichen extracts now provide a vegan source of the same cholecalciferol found in lanolin- or fish-derived supplements. Research shows vitamin D3 raises blood levels more effectively than D2, making lichen D3 a useful choice for vegans and vegetarians, who tend to have lower vitamin D levels. Vitamin D deficiency is common, especially among people with darker skin, older adults, and those with limited sun exposure. However, large trials such as VITAL found that vitamin D supplements do not prevent cancer or heart disease in people with adequate levels. Use lichen D3 to correct or prevent deficiency at recommended doses, not as a cure-all.

Frequently Asked Questions

Is lichen vitamin D3 as good as regular vitamin D3?

Yes. It is the same molecule, cholecalciferol, and should work the same way in the body.

Is vitamin D3 better than D2?

Several studies show D3 raises blood vitamin D levels more effectively than D2.

How much vitamin D should I take?

The RDA is 600 IU daily for most adults and 800 IU over age 70; the upper limit is 4,000 IU unless a clinician advises more.

Do vegans need vitamin D supplements?

Many do, especially in winter or at high latitudes, since vegans tend to have lower vitamin D levels.

Does vitamin D prevent cancer or heart disease?

The VITAL trial found no reduction in cancer or major cardiovascular events with 2,000 IU daily in generally healthy older adults.

References

1. Wang T, Bengtsson G, Kärnefelt I, Björn LO. Provitamins and vitamins D2 and D3 in Cladina spp. over a latitudinal gradient: possible correlation with UV levels. Journal of Photochemistry and Photobiology B. 2001;62(1–2):118–122. PMID 11693362
2. Tripkovic L, Lambert H, Hart K, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. American Journal of Clinical Nutrition. 2012;95(6):1357–1364. PMID 22552031
3. Tripkovic L, Wilson LR, Hart K, et al. Daily supplementation with 15 μg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial. American Journal of Clinical Nutrition. 2017;106(2):481–490. PMID 28679555
4. Forrest KY, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutrition Research. 2011;31(1):48–54. PMID 21310306
5. Crowe FL, Steur M, Allen NE, et al. Plasma concentrations of 25-hydroxyvitamin D in meat eaters, fish eaters, vegetarians and vegans: results from the EPIC-Oxford study. Public Health Nutrition. 2011;14(2):340–346. PMID 20854716
6. Cardwell G, Bornman JF, James AP, Black LJ. A Review of Mushrooms as a Potential Source of Dietary Vitamin D. Nutrients. 2018;10(10):1498. PMID 30322118
7. Manson JE, Cook NR, Lee IM, et al. Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. New England Journal of Medicine. 2019;380(1):33–44. PMID 30415629
8. NIH Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. ods.od.nih.gov

Last updated: October 6, 2026