How to get vitamin D on a vegan diet
Updated: Aug 13
By Ashish Santhalia, Co-Founder, The Vegan School
Vitamin D deficiency is one of the most widespread nutritional issues globally — and it affects vegans and omnivores alike. The dietary routes available on a plant-based diet are narrower, but the answer is not complicated: sunlight where possible, fortified foods where reliable, and a lichen-derived D3 supplement to close the gap.
What Vitamin D Actually Does
Vitamin D functions more like a hormone than a vitamin. Once synthesised in the skin or ingested, it is converted in the liver and kidneys into calcitriol — the active form that regulates calcium absorption, bone mineralisation, immune function, and cellular growth.
Without adequate vitamin D, the intestine absorbs only 10–15% of dietary calcium compared to 30–40% at optimal levels.
Sustained deficiency reduces bone density, increases fracture risk, weakens immune response, and is associated with cardiovascular and autoimmune conditions.
Calcium alone does not build bone. Calcium plus vitamin D does.
Why Sunlight Alone Isn't Enough
The body makes vitamin D when UVB radiation converts 7-dehydrocholesterol in the skin. Three factors interrupt this in most populations.
Latitude. Above 35° North or South, winter UVB is too weak for synthesis for several months. Most of Europe, North America, and much of Asia fall in this zone.
Skin pigmentation. Melanin absorbs UVB. Darker skin needs 3–6× more sun exposure to produce the same amount of vitamin D as lighter skin.
Sunscreen and indoor life. SPF 30 reduces synthesis by approximately 97%. Office work, screens, and pollution do the rest.
Sunlight cannot be relied on for consistent vitamin D in most modern lives.
D2 vs D3 — What the Difference Is
Two supplement forms: D2 (ergocalciferol) and D3 (cholecalciferol). D3 raises and maintains blood 25(OH)D levels more effectively — multiple meta-analyses, including a 2012 review in the American Journal of Clinical Nutrition, show D3 is significantly more bioavailable than D2.
For most of the past, D3 was extracted from lanolin (sheep's wool) and was not vegan. Lichen-derived D3 is now widely available and biochemically identical to lanolin D3.
Both D2 (naturally vegan) and lichen-derived D3 work. Lichen D3 is the more effective choice when available.
Vitamin D in Food
Few foods contain vitamin D naturally. Most comes from fortification.
Fortified plant milks and yogurts. 1.5–2 mcg (60–80 IU) per 240ml serving. Meaningful contributor if consumed daily.
UV-exposed mushrooms. Sun-dried or commercially UV-treated mushrooms contain substantial amounts of vitamin D. Standard supermarket mushrooms contain very little.
Fortified cereals and margarines. Variable — check the label.
The aggregate contribution from plant-based foods is often below the 10 mcg (400 IU) daily recommendation.
How Much Vitamin D Do Vegans Need?
The NHS and most national bodies recommend 10 mcg (400 IU) daily for all adults, particularly during autumn and winter.
Research from the Adventist Health Study-2 found that vegans who did not supplement both calcium and vitamin D had a higher risk of bone fractures than omnivores or lacto-ovo vegetarians. See the broader vegan supplement context for how vitamin D fits alongside B12, omega-3, and iodine.
Some practitioners recommend 25 mcg (1,000 IU) for winter, high latitudes, or darker skin. Higher doses are best guided by a blood test.
Take It With Fat
Vitamin D is fat-soluble. Absorption improves significantly when supplements are taken with a meal containing fat — even 3–5g dramatically increases uptake.
Practical routine: take the supplement at breakfast alongside nut butter, avocado, seeds, or tahini. Absorption is several times higher than with plain water or fruit.
Get Tested
The only reliable way to know vitamin D status is a blood test: the 25-hydroxyvitamin D (25-OH D) test.
Optimal: 50–125 nmol/L (20–50 ng/mL).
Deficient: below 30 nmol/L (12 ng/mL).
Test before increasing supplement dose, when fatigue or bone symptoms appear, or at least once a year in high-risk populations. Full ranges here.
Frequently Asked Questions
Can vegans get enough vitamin D without supplements?
Most cannot consistently year-round. Fortified plant milks contribute and UV-exposed mushrooms help, but aggregate food intake is usually below 10 mcg daily. For most vegans at temperate latitudes, a supplement is the reliable route.
What is the best vitamin D supplement for vegans?
Lichen-derived D3 is the most effective vegan option, performing comparably to lanolin-derived D3 and outperforming D2 in raising blood levels. D2 (ergocalciferol) is naturally vegan and works, but requires higher doses to match D3.
How much vitamin D do vegans need per day?
The NHS recommends 10 mcg (400 IU) daily for adults, particularly in autumn and winter. Higher doses (25 mcg / 1,000 IU) may suit winter, high latitudes, or darker skin — best guided by a blood test.
Does sunlight give vegans enough vitamin D?
In some latitudes and seasons, yes — otherwise no. Above 35° North or South, winter UVB is too weak for skin synthesis. Sunscreen, pollution, and indoor life reduce production even at lower latitudes.
Are vitamin D and calcium related?
Yes — closely. Vitamin D is required for the intestine to absorb calcium efficiently. Without adequate D, dietary calcium is largely unused. Deficiency in one undermines intake of the other.
The Short Answer
Vitamin D deficiency is not a vegan-specific problem — but the dietary routes are narrower. Supplement daily. Prefer lichen-derived D3. Take with a fat-containing meal. Get sunlight when latitude and season permit. Include fortified plant milks and UV-exposed mushrooms as background support.
Test every 12 months if in doubt. A blood panel resolves most questions faster than any guide.
At The Vegan School, nutrition is taught as a core module along with cooking.
Written by Ashish Santhalia Co-founder of The Vegan School, India's first vegan culinary school. He has spent four years teaching plant-based cooking to over 200 students from 30+ countries, and writes about the nutrition questions students ask most. He is not a nutritionist or dietitian — everything here is sourced from published guidance from the NIH, NHS, and from peer-reviewed literature, and is linked so you can check it yourself.
Disclaimer: This article is for general education. It isn't medical or dietary advice. Nutritional needs vary by individual, and supplement requirements, in particular, depend on your health, medication, and blood levels. Speak to a doctor or registered dietitian before starting or changing a supplement.
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