Nutrient deficiencies vegans need to watch out for

Going vegan or veggie is increasingly popular, but it could put you at risk of nutritional deficiencies that impact your health if you don't plan your meals carefully.

If you've started following a vegan diet as part of your 2023 resolutions, it's important to be aware of the nutrients that are harder to source from solely plant-based foods, and make sure you're getting enough. 

We've rounded up the vital vitamins that you may not get from plants, why they matter – and how to get more into your meals.

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Which nutrients are harder to get from a plant-based diet?

Vitamin B12

We only need a small amount of B12 in our daily diet, but it's key to our health. Not getting enough can cause tiredness, headaches and problems with your vision.

If left unchecked, a deficiency can have more severe consequences. It can affect your memory and cognition; or it can lead to vitamin B12 deficiency anaemia, increased risk of heart disease, and nerve symptoms such as numbness.

Vitamin B12 only occurs naturally in animal-derived foods such as meat, milk, eggs, fish and shellfish, so vegans can struggle to get enough of it.

Vegan B12 food sources:

• Fortified breakfast cereal and/or fortified plant-based milk Most cereals have vitamin B12 added to them, but check before you buy (and keep an eye on the sugar content). Some plant-based milk alternatives are also fortified with B12. See how they compare in our guide to plant-based milks. 
• Yeast extract Whether it's Marmite or an own-brand version, these spreads are fortified with vitamin B12. 
• Nutritional yeast Nutritional yeast flakes can be used instead of cheese when you're making vegan dishes such as mac and no-cheese.

However, even if you add fortified foods to your diet, you'll likely need a B12 supplement to ensure you're getting enough.

Calcium

Calcium is found in dairy foods such as cheese, yoghurt and milk; it's needed for strong bones and teeth, as well as regulating heart rhythm.

If we don't get the average 700mg we need per day from our diet, it can lead to reduced bone density. This is particularly important for women, who are at higher risk of osteoporosis in later life.

A 2020 study in Medicine, the British Medical Council journal, showed that those following a vegan diet had a higher risk of fractures in all areas of the body, especially the hips. Vegetarians and fish eaters were also at increased risk of fracture compared to meat eaters.

Vegan calcium food sources:

• Choose calcium-fortified foods Calcium-set soya bean curd or tofu, fortified cereals and fortified plant-based milk alternatives are all useful options.
• Pack in green leafy veg Some are better than others. Kale and spring greens are good sources.
• Don't eat too many foods containing oxalate or phytate Although dried fruits, beans, seeds and nuts contain calcium, they also contain oxalates and/or phytates. These reduce the body's ability to absorb calcium, so try to avoid having these foods at the same time as other calcium sources. The same applies to some dark green leafy veg, such as spinach.

Iron

If you're often tired, breathless and pale,  you might be low in iron, the nutrient needed for healthy blood cells to carry oxygen to every cell in your body.

The 'haem' variety of iron, found in animal products such as beef, lamb, pork, eggs and poultry, is more easily absorbed by the body than plant-derived 'non-haem' iron, which is what animal-free diets depend on.

Vegans have been shown to have a lower blood-cell count and higher levels of iron-deficiency anaemia than people who get iron from animal sources.

How to get enough iron when you're vegan:

• Combine it with vitamin C This improves absorption of iron, so combining vitamin C-rich fruit and veg, or a glass of OJ, with your iron-based sources (beans, pulses, nuts, seeds, dried fruit, wholemeal bread) can help. 
• Avoid drinking tea or coffee with meals Tea and coffee contain plant compounds called polyphenols, which can bind to iron and reduce how much you absorb, so try to avoid drinking them near to mealtimes. 

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Zinc

Zinc supports immunity, healthy hair and skin, and wound healing. Animal sources it's found in include meat, shellfish and dairy foods.

It's known as a trace mineral, meaning we only need small amounts, but our bodies can't store it, so we need a regular intake. 

Plant-based sources of zinc include wheatgerm, beans, nuts, seeds, mushrooms and fortified breakfast cereals, but phytate (found in plant fibres, especially in seeds and nuts) can inhibit zinc absorption.

Vegan zinc food sources:

• Try fermented foods like tempeh and miso The fermentation process in these soya foods produces the enzyme phytase, which breaks down the phytates in plant foods that can get in the way of zinc absorption.
• Sprouted beans, chickpeas and lentils Sprouting also leads to the breaking down of phytates, but cook them thoroughly if you're serving them to anyone in a vulnerable group, such as a pregnant woman.

Omega-3 fats

The omega-3 fats ALA,  EPA and DHA have to come from our food, because we can't make them ourselves.

EPA and DHA, which are needed for heart, lung and blood vessel health, are found in oily fish such as salmon, mackerel, herring and sardines (ideally two portions per week), so if you're vegan you rely on these being converted from the ALA you get from certain nuts and seeds.

Foods rich in the omega-6 essential fat linoleic acid (LA) include walnuts, sunflower and pumpkin seeds and some vegetable oils including sunflower and corn.

Vegan sources of omega-3 fats:

• Chia seeds, ground linseed, hemp seeds and walnuts All are good daily sources.
• Use rapeseed oil The Vegan Society recommends using this instead of oils containing a lot of LA, such as sunflower, corn or sesame.

Pescatarian? See our guide on how to buy sustainable fish

Iodine

Iodine is needed for healthy thyroid function, which impacts many processes in the body, including metabolism and temperature control, as well as being essential for healthy pregnancy.

The 140mg of it that we need each day is usually derived from dairy products and seafood, but if you're a vegan, or don't eat much of these food groups, you may risk being deficient.

A 2021 study published in Cambridge University Press found that both vegans and vegetarians are at risk of inadequate iodine nutrition.

Vegan iodine food sources:

• Eat seaweed, but not too often Although seaweed foods such as sushi, nori, wakame and kelp contain iodine, it can be in variable amounts, so guidance states that you shouldn't eat sea vegetables more than once a week.
• Don't rely on iodised salt Experts say that, as we are being encouraged to cut down on salt to prevent conditions such as high blood pressure, we shouldn't rely on iodised salt as a means of increasing intake.
• Use iodine-fortified plant milk The ingredient to look out for is potassium iodide, but read the label, as some milk alternatives contain it while others don't. 

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Are vegan diets healthy?

A well-balanced vegan diet is low in saturated fat and rich in dietary fibre and plant proteins – all of which combine to benefit your health in a variety of ways, including weight loss, reduced risk of some cancers, managing blood-sugar levels and reducing levels of bad cholesterol.

However, it's also possible to have an unhealthy vegan diet. Some ultra-processed foods labelled as vegan, such as meat substitutes, aren't always as healthy as their image may suggest.

Some have unexpectedly high levels of sugar, salt and fat. For example, Which? compared a vegan Beyond Burger to a standard beef burger and found more calories, fat and salt per 100g in the non-meat version. They can be pricier, too.

So, don't assume any food labelled vegan is good for you. You'll still need to watch out for additives, and high sugar or salt levels.

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Who's most at risk of nutrient deficiency?

Certain groups are more at risk of lacking key vitamins and minerals:

Women and teenage girls

The National Diet and Nutrition Survey shows that one in four UK women and almost half (49%) of girls and young women aged 11-18 have a low intake of iron, which can increase the risk of iron deficiency anaemia.

The needs of women aged 19-50 are greater than those of men and older women because of menstruation, which can use up your iron reserves, especially if your periods are heavy or your diet is low in iron.

Around one in 10 adult women also have inadequate intakes of calcium, which may leave them at higher risk of osteoporosis, and there is evidence that teenage girls and young women don't get enough iodine.

Older people

As we get older it becomes harder to absorb vitamin B12, so experts recommend boosting levels by eating fortified breakfast cereals, yeast extract and meat.

The NHS says that a deficiency in both vitamin B12 and folate are more common in older people, affecting around one in 10 over 75 and one in 20 aged 65-74, so if you're concerned see your GP.

Vegetarians

How strictly vegetarian you are will impact which nutrients you might be lacking (for example, if you still eat fish or eggs). However, with the emphasis on plant foods, vegetarians should be thinking about how to meet your vitamin B12 needs, for example, from fortified foods or by taking a supplement.

People with gastrointestinal issues or on certain medications

Some gastric conditions make it hard for your body to absorb nutrients from food.

For example, people with coeliac disease, where the digestive system works less effectively than it should, need to make sure they have enough iron, vitamin B12 and calcium. Some reflux-suppressing medications can also limit B12 uptake.

What about supplements?

It's best to get your nutrients from your diet where possible. However, supplements may be helpful for some groups or where nutrients are harder to get from your diet alone. See our guide to vitamin and mineral supplements you do and don't need for more.

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