Vitamin D for Vegans and Vegetarians in Australia: Testing Guide
Last updated: May 2026
If you eat plant-based, vitamin D is one of the few nutrients where dietary intake genuinely doesn't carry you. There's almost no naturally-occurring vitamin D in plant foods. The body makes vitamin D from sunlight, supplements it from food when it can, and stores what it doesn't immediately use — and vegan and vegetarian eaters tend to come up short on the storage side because most reliable dietary sources are animal-derived.
That doesn't mean plant-based eating causes deficiency. It means status depends entirely on sun exposure and supplementation rather than diet — and Australians on plant-based diets need to actually verify their status rather than assume the sunshine handles it.
This guide explains where vitamin D actually comes from for vegans and vegetarians in Australia, what the published research shows about deficiency rates in plant-based populations, which supplements work, and how to test cleanly.
If you'd like the basics first, see What vitamin D actually is. For the broader food-source discussion, our guide to foods high in vitamin D goes through every meaningful source (and the gap they leave behind).
Why diet alone doesn't cover vitamin D for plant-based eaters
The foods generally cited as "good" vitamin D sources are almost all animal-derived: oily fish (salmon, mackerel, sardines), egg yolks, cod liver oil, and full-fat dairy that's been fortified. Beef liver carries some. Pasture-raised animal products carry slightly more.
Plant sources are limited to:
- UV-exposed mushrooms (specifically those grown or treated with ultraviolet light). These produce vitamin D2 — less effective than D3 at raising 25(OH)D, but real nonetheless.
- Fortified plant milks, fortified breakfast cereals, fortified plant-based yogurts. Fortification amounts vary widely; many provide only ~25–40% of an adult's daily RDI per serving.
- That's it. The list ends there.
This isn't a critique of plant-based eating — it's a structural reality. Plant-based diets are nutritionally complete with supplementation. Vitamin D is one of three nutrients (along with B12 and omega-3 DHA/EPA) where supplementation is genuinely required for most plant-based eaters, rather than optional.
What the research shows about deficiency rates
Multiple studies of vegan and vegetarian populations in Western countries show higher rates of vitamin D deficiency than omnivores — not dramatically higher, but consistently higher. In some northern-European cohorts, vegan groups have shown 40–60% deficiency rates vs 20–30% in omnivore comparisons. Australian data follows similar patterns, though the absolute deficiency rates are lower because of better year-round UV in most of the country.
Two confounders worth flagging:
- Plant-based eaters as a group tend toward healthier overall lifestyle patterns — outdoor time, exercise, less sun-avoidance — which partially offsets the dietary gap.
- Plant-based eaters in southern Australia, in winter, are at meaningfully higher deficiency risk than the same demographic in Brisbane or Cairns.
The point isn't "vegans are deficient" — it's "vegans who don't supplement and live in low-UV environments are at meaningfully elevated risk and should actually test, not assume."
See how common vitamin D deficiency is in Australia for the general-population picture.
D2 vs D3 — the supplement form question
This is the single most important practical question for plant-based eaters, because most cheap vitamin D supplements are D3 derived from sheep's wool (lanolin) — not vegan.
Vegan-friendly options:
- D3 from lichen. A specific lichen species produces cholecalciferol (D3) naturally. Lichen-derived D3 is now widely available in Australian health food stores and online. This is the preferred option — same active form as animal-derived D3, with equivalent bioavailability.
- D2 (ergocalciferol). Typically derived from UV-exposed yeast or fungi. Less effective than D3 at raising and maintaining 25(OH)D, and has a shorter half-life. Cheaper and widely available, but you may need a higher dose to achieve the same blood-level result.
If you're testing your level (and you should be — see below), D2 vs D3 distinction matters less because you can adjust based on what your blood actually shows. If you're not testing and just "taking a supplement," the form matters more because D3 is more forgiving of dose imprecision. Our guide to taking vitamin D supplements covers timing, food pairing, and cofactor questions in more detail.
What level should you aim for?
The same Australian reference ranges apply regardless of diet:
| Level (nmol/L) | Interpretation |
|---|---|
| <25 | Severe deficiency — clinical action warranted |
| 25–49 | Deficiency — supplementation indicated |
| 50–74 | Sufficient but low end |
| 75–125 | Optimal range |
| >125 | Above the optimal range cited in most clinical literature |
Most healthy adults feel best in the 80–120 nmol/L range. There's no published benefit to chasing higher than that.
How to test as a plant-based Australian
The three options:
- GP-ordered Medicare-rebated test. Medicare covers 25(OH)D testing in specific high-risk groups (institutionalised, dark-skinned, malabsorption conditions, certain medications, etc.). Being vegan or vegetarian on its own doesn't qualify you. If your GP identifies clinical concern, they can order it; otherwise it'll be out-of-pocket.
- Private pathology centre visit. Pay out-of-pocket for a 25(OH)D test, blood drawn at a centre. Standard accurate venous method.
- At-home dried blood spot test. Finger-prick at home, post the sample in, get results by email. The method that matters is mass spectrometry (ID LC-MS/MS) analysis in an accredited lab — lateral-flow rapid strip tests are too inaccurate to base supplementation decisions on. Our honest answer on at-home test accuracy covers what to ask before buying.
If convenience is what stops you from testing, the at-home DBS option removes that barrier. Our Vitamin D Test uses ID LC-MS/MS — the same reference method published research uses — with detail on the lab process on the Our Method page. The choice of brand matters less than the choice of analytical method.
A reasonable plant-based supplementation pattern
Talk to your GP for personalised advice, but the broad pattern most plant-based Australians settle into:
- Year-round: 1000–2000 IU/day vegan D3 (lichen-derived) or D2 equivalent if D3 isn't available.
- Winter in southern states: 2000–4000 IU/day during the May–August window. See our winter guide for the UV-index physics behind why southern winters are so unforgiving.
- If deficient on test: 4000+ IU/day for 8–12 weeks then retest. Severe deficiency may need a GP-supervised loading dose.
- If sufficient on test: Maintenance dose continues. Retest in 6 months to confirm stability.
The retest is the part most people skip. Taking a supplement is not the same as knowing your level responded — some plant-based eaters discover their cheap D2 supplement isn't moving the needle and switch to lichen-derived D3 after seeing it on paper.
The UV-exposed mushroom angle
It's a real source, but not a complete one. A serving of UV-exposed white button mushrooms (~100g) can provide 400–800 IU of vitamin D2 — enough to make a meaningful contribution to daily intake, but not enough to be your sole source. Mushrooms that haven't been UV-exposed (most supermarket mushrooms, unless labeled) provide essentially no vitamin D.
If you're already eating UV-exposed mushrooms regularly plus taking a 1000–2000 IU vegan supplement, your contribution from food is meaningful. If you're relying on mushrooms alone, you're under-dosing significantly.
What about vegetarians who eat dairy and eggs?
Vegetarians (lacto-ovo) have a slightly easier dietary path than vegans because fortified dairy products and egg yolks contribute some vitamin D. But the contribution is still typically below daily requirement — most Australian fortified milk provides 80–100 IU per 250ml serving, and Australian eggs vary widely depending on the hen's diet and access to sunlight.
Practically, vegetarians can sometimes get away without supplementation if they're outdoor-active, in northern Australia, and eat fortified dairy daily. But the safer assumption — particularly through winter in southern states — is that supplementation plus testing is needed regardless.
Frequently asked questions
Is vegan vitamin D3 from lichen as effective as animal-derived D3?
Yes. The molecule (cholecalciferol) is identical regardless of source. Published bioavailability studies show no meaningful difference between lichen-derived and lanolin-derived D3 in their ability to raise 25(OH)D. Lichen D3 has historically been more expensive but pricing has equalised in recent years.
Can I get enough vitamin D from UV-exposed mushrooms alone?
Realistically, no — unless you're eating 200+ grams of specifically UV-exposed mushrooms daily, which most people don't. Mushrooms contribute meaningfully to dietary intake but aren't a complete substitute for supplementation and sun exposure combined.
Do plant-based eaters need to test more often than omnivores?
Yes — particularly the first time, to establish a baseline. After that, a once-yearly winter test is usually sufficient for stable plant-based eaters who've found a supplementation routine that holds them in the optimal range.
Does B12 deficiency affect vitamin D status?
Not directly. They're separate nutrients with separate metabolic pathways. But plant-based eaters who haven't addressed B12 supplementation often also haven't addressed vitamin D — the same lifestyle pattern that causes one gap often causes the other.
Is vitamin D from fortified plant milks enough?
Usually not on its own. Most fortified plant milks (oat, soy, almond) provide ~75–125 IU per 250ml serving — helpful but well below the 1000–2000 IU/day target for most adults. Treat fortified products as a small contribution, not your primary source.
What about K2 with vitamin D for vegans?
Vitamin K2 (menaquinone) is often paired with D3 in supplements because of theoretical synergy in calcium handling. Vegan K2 (typically from natto fermentation, MK-7 form) is available. The synergy is real but modest — not a deal-breaker if your supplement only contains D3.
Bottom line
Plant-based eating doesn't cause vitamin D deficiency — lack of supplementation and insufficient sun exposure do. Vegans and vegetarians in Australia need to actually verify their status, not assume diet has them covered. Vegan-friendly D3 (lichen-derived) works just as well as animal-derived D3. The cheapest mistake is taking any supplement without ever testing whether it actually moved your level.
Test once a year minimum (late winter is the highest-value timing in southern states). Choose a methodology that's accurate enough to base supplementation decisions on — mass spectrometry analysis in an accredited lab. The brand matters less than the lab method.
If you'd like to test at home, our Vitamin D Test uses ID LC-MS/MS in an accredited Australian lab — same method used in published vitamin D research — with results posted to your email within 3–5 business days.