Do I need blood tests?

A baseline (B12, ferritin, vitamin D, TSH) is worth doing once. Repeat every 1–2 years, or sooner if fatigue or symptoms appear. Standard medical advice — not vegan-specific.

Can I get everything from food without supplements?

Everything except B12. Wild plant foods don't reliably contain it, and modern hygiene means we no longer get it incidentally from soil or water. A cheap tablet solves this permanently.

Tool · Self-check

Vegan nutrient checker

8 quick questions to spot gaps in the nutrients that matter most on a plant-based diet — with food sources and supplement guidance for each.

Progress

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Vitamin B12

250 µg/day or 2500 µg/week

Do you take a B12 supplement or eat fortified foods daily?

Sources: Cyanocobalamin supplement, fortified plant milks, nutritional yeast

Vitamin D

1000–2000 IU daily

Do you get 15+ min of midday sun or take a D3 supplement?

Sources: Sunlight, D3 supplement (lichen-derived), fortified soy milk

Iodine

150 µg/day

Do you use iodised salt or take an iodine supplement?

Sources: Iodised salt, kelp (careful — high), a 90–150 µg supplement

Iron

8 mg (men), 18 mg (menstruating women)

Do you eat legumes + vitamin C daily (e.g. beans + tomato)?

Sources: Lentils, chickpeas, tofu, tempeh, pumpkin seeds, oats

Zinc

8–11 mg/day

Do you eat beans, nuts or seeds most days?

Sources: Pumpkin seeds, cashews, lentils, tempeh, oats, whole grains

Omega-3 (DHA/EPA)

250–500 mg DHA+EPA or 2 tbsp flax daily

Do you take algae oil or eat flax/chia/walnuts daily?

Sources: Algae oil (DHA+EPA direct), flax, chia, walnuts (ALA precursor)

Calcium

1000 mg/day (1200 mg over 50)

Do you drink fortified plant milk or eat calcium tofu daily?

Sources: Fortified soy milk, calcium-set tofu, kale, bok choy, tahini

Protein

0.9–1.2 g/kg body weight

Do you eat legumes, tofu or tempeh at 2+ meals per day?

Sources: Tempeh, tofu, lentils, chickpeas, seitan, edamame, soy milk

Your snapshot

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Your snapshot

Answer above to see your gaps.

FAQ

Is this a diagnosis?

No — it's a planning checklist. If you have symptoms (fatigue, hair loss, tingling, breathlessness) or have been vegan >1 year without supplements, book a blood panel: B12 (with MMA), ferritin, vitamin D and TSH cover the most common gaps.

Do I need to test every year?

A baseline panel in your first year vegan, then every 2–3 years if all levels are optimal and supplementation is consistent. Test annually during pregnancy, adolescence, or endurance training blocks.

Can I get all of this from food?

Every nutrient except B12 — where a supplement or fortified food is essential for everyone on a vegan diet, and recommended for most people over 50 regardless of diet.

Explore health hub Plan a balanced week

Key takeaways

Only four nutrients truly need planning on a vegan diet: B12, vitamin D, omega-3 (algae) and iodine. The rest arrive with a varied plate.
B12: 2,000 µg cyanocobalamin weekly, or 25–100 µg daily. No exceptions — this is the one non-negotiable supplement.
Iron: legumes, tofu, whole grains, greens. Pair with vitamin C (peppers, citrus, tomatoes) to boost absorption.
Calcium: fortified plant milks, tofu set with calcium, tahini, kale, bok choy, dried figs.

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Frequently asked questions

B12 always requires a supplement or fortified foods. Vitamin D at high latitudes. Iodine if you don't eat iodised salt or seaweed. Omega-3 DHA/EPA is easily covered by an algae supplement.

Keep reading

Health

The evidence base for a well-planned vegan diet.

Ingredients

Where each nutrient lives in a plant-based pantry.

Meal planner

Build weeks that cover the numbers.

The nutrients worth tracking on a plant-based diet

Only a short list of nutrients requires deliberate attention. Tracking everything produces fatigue; tracking these five produces adequacy.

B12 is the only absolute

Vitamin B12 is produced by bacteria, not by plants or animals; farmed animals frequently receive it as a supplement themselves. There is no reliable plant food source — not tempeh, not spirulina, not nori, all of which contain inactive analogues that can even interfere with absorption. Either a supplement of 50 µg daily or 2,000 µg weekly, or consistently fortified foods, is required. Deficiency develops slowly and can cause irreversible neurological damage, which is why this one is non-negotiable.

Iron, zinc and the absorption trick

Plant iron is non-haem and absorbed less efficiently, but absorption is highly responsive to context. Vitamin C taken at the same meal can multiply uptake several-fold; tea, coffee and calcium supplements taken with the meal suppress it. Soaking, sprouting and fermenting legumes and grains reduces phytate and improves both iron and zinc availability. Plant-based eaters typically have lower ferritin but not higher rates of anaemia in most cohorts.

Omega-3, iodine and vitamin D

ALA from flax, chia and walnuts converts to EPA and DHA inefficiently — commonly cited at 5–10% and lower still for DHA — so an algal oil supplying 250 mg combined EPA/DHA daily is a reasonable insurance policy. Iodine is easy to miss because most plant milks are not fortified with it; iodised salt or a supplement covers it, and both deficiency and excess from heavy seaweed use carry thyroid risk. Vitamin D is a shared issue across all diets at higher latitudes in winter.

Calcium is easier than its reputation

Calcium-set tofu, fortified plant milks, tahini, almonds, and low-oxalate greens such as kale, bok choy and broccoli all deliver well-absorbed calcium — kale's absorption fraction is actually higher than milk's. Spinach is the exception: its oxalate binds calcium and makes it largely unavailable, which is why it should not be counted toward a target.

Daily targets and reliable sources

Adult targets; requirements rise in pregnancy and lactation.

Nutrient	Adult target	Reliable plant sources	Supplement?
Vitamin B12	2.4 µg (or 50 µg/day supplement)	Fortified foods only	Yes — always
Vitamin D	10–20 µg	Fortified foods, sunlight	In winter
Iodine	150 µg	Iodised salt, measured seaweed	Often
Omega-3 EPA/DHA	250 mg	Algal oil	Recommended
Iron	8–18 mg	Lentils, tofu, seeds, oats	If ferritin is low
Zinc	8–11 mg	Legumes, seeds, wholegrains	Rarely
Calcium	700–1000 mg	Calcium-set tofu, fortified milks, kale	Rarely
Selenium	55 µg	Brazil nuts (1–2 per day)	No

A sane tracking routine

Track a normal week once

One week of honest logging tells you which of the five is actually short. Most people find only one gap.

Fix gaps structurally

Change a recurring food rather than adding a daily task — calcium-set tofu instead of plain, iodised salt instead of sea salt.

Test rather than guess

Ferritin, B12 (with MMA or holotranscobalamin if borderline) and 25-OH vitamin D are inexpensive and settle the question.

Re-check annually

After the first year, an annual blood panel is enough for most healthy adults.

Absorption in practice

Improves uptake

Vitamin C with iron-rich meals — peppers, citrus, tomatoes.
Soaking and sprouting legumes and grains.
Fermented foods such as tempeh and sourdough.
Spacing calcium supplements away from iron-rich meals.

Reduces uptake

Tea and coffee with meals rather than between them.
Counting spinach toward calcium targets.
Relying on spirulina, nori or tempeh for B12.
Daily large seaweed portions, which can overshoot iodine badly.

Nutrient questions

Do I need a multivitamin?

Not necessarily. A targeted B12 supplement, an algal oil, and vitamin D in winter covers most people more precisely and more cheaply than a broad multivitamin.

How quickly does B12 deficiency appear?

Liver stores can last two to five years, which is why new plant-based eaters often feel fine for a long time before symptoms emerge. That delay is the risk, not a reassurance.

Is low ferritin dangerous?

Low ferritin without anaemia is common and not automatically harmful, but persistent fatigue with low ferritin is worth treating. Discuss supplementation with a clinician rather than self-dosing iron, which has real risks.

Should children take the same supplements?

B12 and vitamin D yes, at paediatric doses. Iodine and omega-3 are worth discussing with a paediatric dietitian, particularly under two years old.

Are these issues unique to vegans?

No. Vitamin D and iodine insufficiency are widespread across all diets, and B12 deficiency is common in older omnivores because absorption declines with age.