Key Nutrients On A Plant-Based Diet (And Simple Ways To Cover Them)

Vitamin B12

Why it matters: Vitamin B12 is crucial for red blood cells, nerve function and DNA synthesis. Deficiency can cause anaemia, fatigue and neurological problems (1,4).

What the research says: Reviews consistently identify B12 as the key nutrient of concern in vegan diets, because it's not reliably present in unfortified plant foods (1–4). Vegans who do not use supplements or fortified foods regularly almost always show lower B12 status and higher risk of deficiency (2,4).

Simple ways to cover it:

• Use fortified foods most days – nutritional yeast ("nooch"), fortified plant milks, breakfast cereals, and yeast spreads like Marmite often contain B12 (check the label) (3,5,6).
• Follow guidance to either eat B12‑fortified foods at least twice daily aiming for around 3 micrograms per day, or take a B12 supplement such as 10 micrograms daily or 2000 micrograms weekly (5,6).
• For most fully plant-based eaters, a B12 supplement plus some fortified foods is the simplest, most reliable approach (1–4).

Vitamin D

Why it matters: Vitamin D supports bone health, immunity and muscle function (3,5). In the UK, many people – regardless of diet – have low vitamin D, especially over autumn and winter (3).

What the guidance says: UK guidance suggests that everyone should consider a daily vitamin D supplement, particularly between October and March, and some may benefit year‑round (3). Vegan diets can be low because most natural sources are animal-based and sun exposure is often limited (1–3).

Simple ways to cover it:

• Sensible sun exposure in spring and summer when possible.
• Fortified plant milks, spreads and yoghurts with added vitamin D (check labels) (3).
• A vitamin D supplement (often D2 or vegan D3), with dose tailored to you – something we can personalise based on your bloods and risk factors (1,3).

Iodine

Why it matters: Iodine is essential for thyroid hormones, which regulate metabolism, energy and growth (1,2).

What the research says: Vegan diets often have lower iodine intakes and lower iodine status than omnivorous diets, especially where iodised salt isn't routinely used (1,2,7). The 2025 review on vegan deficiencies highlights iodine as a recurrent issue if no strategy is in place (2).

Simple ways to cover it:

• Use iodised salt at home if appropriate for your blood pressure and health context (1,2).
• Include small amounts of seaweed such as nori or wakame; avoid very large amounts of kelp, which can provide excessive iodine (1,2).
• Consider a supplement that includes iodine, particularly if you don't use iodised salt or seaweed regularly – something we can decide together based on your diet and labs (1,2).

Seaweed is powerful; a little goes a long way, so it's worth getting this one right.

Omega‑3 fats (ALA, EPA, DHA)

Why they matter: Omega‑3 fats are involved in heart health, brain function and vision (1,2). On a vegan diet, you get ALA from plants, and your body converts some of it into EPA and DHA.

What the research says: Vegan diets typically provide less preformed EPA and DHA than omnivorous diets, and blood levels can be lower on average (1,2). Health outcomes are still generally favourable, but a sensible omega‑3 strategy is recommended, especially for certain groups (1,2).

Simple ways to cover them:

• Aim for daily ALA sources: ground flaxseed, chia seeds, hemp seeds and walnuts are your go‑tos (1,2,5).
• Use rapeseed (canola) oil as a main cooking oil for extra ALA.
• Many people choose to add an algae-based EPA/DHA supplement, especially if they don't regularly eat ALA-rich foods or have higher needs – something to individualise if we work together (1,2).

Iron

Why it matters: Iron is needed for haemoglobin and oxygen transport; low iron can cause fatigue, weakness and reduced exercise capacity (1,3,5).

What the research says: Vegan diets can actually be quite high in iron on paper, but plant (non‑haem) iron is less readily absorbed than haem iron from meat (1–3). Reviews flag iron as a nutrient to watch, especially for menstruating women, athletes and those with higher requirements (1,2).

Simple ways to cover it with food:

• Build in iron-rich plant foods daily: beans, lentils, chickpeas, tofu, tempeh, wholemeal bread, fortified cereals, nuts, seeds and dark green leafy veg (3,5,6).
• Pair iron-rich foods with vitamin C sources (e.g. peppers, berries, citrus, kiwi, broccoli) to boost absorption (1,5,6).
• Avoid tea and coffee with meals, as they can reduce iron absorption (5,6).
• If you have a history of low iron or symptoms, blood tests and tailored advice (including possible supplementation) are key.

Calcium

Why it matters: Calcium is vital for bones, teeth, muscle contraction and nerve signalling (1,3,5).

What the research/guidance says: Vegan diets can meet calcium needs, but only if you deliberately include calcium-rich foods (1–3,5). Without this, intake is often below recommendations in vegans (1,2).

Simple ways to cover it:

• Choose calcium-fortified plant milks and yoghurts (aim for around 120 mg calcium per 100 ml in milks – check labels) (3,5).
• Include tofu set with calcium sulphate, as well as tahini, almonds and some leafy greens like kale and pak choi (1,3,5).
• A simple pattern is: fortified milk in drinks and breakfast, tofu a few times a week, plus greens and tahini.