Vegetarianism is the practice of a diet that excludes the consumption of certain animal products, including red meat, poultry, fish and seafood. Other animal diets may also be excluded such as eggs, and instead, the diet focuses on plant based foods, including beans and legumes, grains, fruits and vegetables, nuts and seeds. There are different types of vegetarian diets, such as:
- Lacto-vegetarians: No meat, fish, and eggs but does include dairy products such as milk, yoghurt and cheese.
- Ovo-vegetarians: Exclude meat, fish, and all dairy but includes eggs.
- Lacto-ovo vegetarians: Exclude meat and fish but includes all dairy products and eggs.
Veganism excludes all animal products, not just meat and fish. This includes dairy products and eggs, as well as foods produced by animals, such as honey. The vegan diet consists of only foods that are derived from plants, such as beans, lentils and legumes, soy, grains, fruits, vegetables, nuts & seeds.
A vegan and vegetarian diet can provide the body with a wide range of vitamins and minerals. For example, grains and legumes are a good source of many B vitamins, as well as magnesium and potassium, and vegetables provide a good source of vitamins A, C and E, as well as vitamin K. However, it is important to note that because vegetarian and vegan diets exclude certain foods, some nutrients can be harder to obtain and need to be carefully planned for, such as vitamin B12, iodine, calcium, omega 3 fatty acids and iron, to name a few.
Being able to obtain nutrients from a plant based diet requires a diversity in food choices, meaning someone needs to eat foods from all plant groups, as well as considering certain supplements for particular nutrients. It can be seen to be harder to obtain nutrients from a vegetarian and vegan diet compared to an omnivorous diet, however, we will discuss how to ensure you are meeting your requirements. Without careful planning and consideration, deficiencies are more likely to occur, which can lead to health issues in the future.
Specific nutrients required on a vegetarian and vegan diet will be discussed in detail, giving examples of what specific foods to include in your diet to meet your nutritional requirements, as well as any factors to consider around the absorption of nutrients when following a vegan or vegetarian diet.
Vitamins and minerals that vegetarians can lack
Vegetarians can potentially risk becoming deficient in a certain number of nutrients, mainly because these nutrients are more commonly found in animal based products. These include:
Nutrient | Why might vegetarians lack this nutrient | Requirements (UK) | % of vegetarians deficient |
Vitamin B12 | B12 is mainly found in animal products, although dairy is a good source | 1.5mg per day for all adults | 40% of vegetarians can be deficient |
Vitamin D | Main source includes sunlight, as well as dairy | 600 IU per day for adults, 800 IU per day for pregnant and lactating women and the elderly. | Up to 33% of vegetarians have been shown to be deficient |
Iron | Plant based iron is poorly absorbed compared to animal based iron | 8mg/day for men and post-menopausal women. 14mg/d for pre-menopausal women | Between 12% to 79% of vegetarians, higher in females |
Zinc | Found in higher concentrations in animal sources | 9.5mg a day for men 7mg a day for women | 33% of vegetarians have levels of zinc lower than reference range |
Omega 3 fatty acids | Fish is the main source of omega 3, though there are some vegetarian and vegan sources, however the type of omega 3 is not optimal, and conversion levels are poor. | No official recommendation for omega 3. However, 250-500mg/day supplementation is often quoted to be best. | Research shows that vegetarians and vegans have up to 50% less EPA and DHA concentration (forms of omega 3) compared to omnivores. |
Vitamins and minerals that vegans can lack
Along with the nutrients mentioned in the previous section, there are an additional two nutrients that those who follow a vegan diet should be mindful of, as they have a higher risk of developing deficiencies in these:
Nutrient | Why might vegans lack this nutrient | Requirements (UK) | % of vegans deficient |
Calcium | Fewer vegan sources of calcium, except fortified plant milks and soy products and some seeds | Adults requirements are 700mg per day. | No data for vegans specifically, but estimates of 50% of the world population have inadequate dietary calcium |
Iodine | Mainly found in animal products and dairy, few vegan sources that are not commonly found in a Western diet | 140μg a day for adults. | 80% of vegans suffer from iodine deficiency |
Before starting supplementation on any of the above, we recommend speaking to a health professional to ensure you need a supplement and are choosing a high quality supplement with the right dose.
Vegetarian and vegan vitamin deficiency symptoms
Vitamin deficiencies can develop slowly, so it is important to look for these sometimes subtle signs of deficiency, if you are vegetarian or vegan.
Vitamin B12 deficiency symptoms:
- Fatigue and weakness
- Shortness of breath
- Tingling in hands and feet
- Memory problems and cognitive difficulties
- Mood changes, such as depression and irritability
- Glossitis (inflammation of the tongue) and mouth ulcers
Vitamin D deficiency symptoms:
- Slow wound healing
- Mood swings and depression
- Bone pain and muscle weakness
- Fatigue and tiredness
- Hair loss
Iron deficiency symptoms:
- Fatigue and weakness
- Paling of the skin
- Shortness of breath
- Dizziness
- Very cold hands and feet
- Weak and brittle nails and hair loss
- Heart palpitations
Calcium deficiency symptoms:
- Muscle cramps and spasms
- Tingling and numbness in fingers
- Poor appetite
- Irregular heart rhythms
- Bone pain
- Dry skin and brittle nails
Zinc deficiency symptoms:
- Poor immune response, leading to frequent bouts of infection
- Hair loss
- Skin acne
- Delayed wound healing
- Loss of taste and smell
Omega 3 fatty acids deficiency symptoms:
- Dry skin
- Fatigue and weakness
- Poor concentration
- Mood swings and depression
- Joint pain and stiffness
For those who follow a vegan diet with no consumption of dairy products, risk of iodine deficiency is higher.
Iodine deficiency symptoms:
- Goitre (enlarged thyroid gland- lump or swelling at the bottom of your neck)
- Hypothyroidism symptoms, such as fatigue and weight gain
- Dry hair and skin
- Cognitive impairment
What vegetarians and vegans should eat to get the necessary vitamins?
Consuming a wide variety of vegetarian foods will help to ensure that you are obtaining the essential vitamins and minerals from your diet, without the need for heavy supplementation. Here are key nutrients and what foods to find them in:
Vitamin B12:
- Eggs
- Milk, cheese and yoghurt
- Lentils, chickpeas, legumes
- Tofu & soy products
- Fortified cereals
- Dried fruits
- Nuts
- Fortified whole wheat bread
Vitamin D:
- Milk, cheese and yoghurt
- Eggs
- Mushrooms exposed to sunlight
- May need a supplement as the sunlight is the best source of vitamin D
Calcium:
- Milk, cheese and yoghurt
- Tofu & soy products
- Leafy greens e.g. kale & pak choi
- Chia seeds, sunflower seeds and almonds
- Dried figs
Iodine:
- Eggs
- Milk and yoghurt
- Nori seaweed
Iron:
- Lentils and beans
- Tofu and soy products
- Fortified cereals
- Sesame seeds, pumkin seeds, cashews and almonds
Zinc:
- Lentils and beans
- Nuts and seeds
- Whole grains e.g. quinoa and wholegrain rice
- Tempeh
- Sesame seed and tahini
Omega 3 fatty acids:
- Walnuts, flax seeds & chia seeds
- Algae based supplements may be recommended
What vegans should eat to get the necessary vitamins?
Planning well to include a variety of vegan and plant foods can reduce the risk of deficiency. Some nutrients, such as iodine, vitamin B12 and vitamin D may need to be supplemented, due to low food sources on a vegan diet.
Vitamin B12:
- Fortified plant milks
- Lentils, chickpeas, legumes
- Tofu & soy products
- Fortified cereals
- Dried fruits
- Nuts
- Fortified whole wheat bread
- Nutritional yeast (fortified)
Vitamin D:
- Fortified plant milks and yoghurts
- Mushrooms exposed to sunlight
- May need a supplement as the sunlight is the best source of vitamin D
Calcium:
- Fortified plant milks and yoghurts
- Tofu & soy products
- Leafy greens e.g. kale & pak choi
- Chia seeds and almonds, sunflower seeds
- Dried figs
Iodine:
- Nori seaweed and some fortified plant milks
- Supplement may be recommended
Iron:
- Lentils and beans
- Tofu and soy products
- Fortified cereals
- Sesame seeds, pumkin seeds, cashews and almonds
Zinc:
- Lentils and beans
- Nuts and seeds
- Whole grains e.g. quinoa and wholegrain rice
- Tempeh
- Sesame seed and tahini
Omega 3 fatty acids:
- Walnuts, flax seeds & chia seeds
- Algae based supplements may be recommended
Can vegetarians and vegans have a healthy diet without supplements?
Yes, vegetarians and vegans can have a healthy diet without the need of various supplements. There are a few exceptions to this, however the key is to ensure you are planning your diet well, to ensure you are consuming all types of plant foods regularly, to maximise your nutrient intake. Choose cooking techniques which allow you to retain and absorb more of the nutrients, such as soaking pulses before cooking and trying to steam vegetables rather than boiling to prevent nutrient loss in the water. Also, using healthy fats can support absorption of nutrients - this is detailed further below.
Consulting a dietitian for a plant based diet can help you to ensure that you are having the best possible vegan or vegetarian diet, without the need for supplementation.
There may be cases of supplementation needed, if for example you are unable to consume adequate quantities of seeds and nuts due to allergies, then an omega 3 supplement may be advised. Or if you prefer to have organic plant based milk compared to a fortified plant based milk, an iodine supplement may be advised as vegan sources of iodine are low, aside from kelp and nori (seaweed), which is not often found in Western diets.
If you have other allergies or dietary preferences that can limit your food intake, this is where discussing with a health professional will help you make the best informed choices in regards to the need to supplement.
Which supplements should vegetarians and vegans choose?
Certain supplements may be advised if you struggle to obtain certain nutrients through your diet alone. These include:
Vitamin D supplements
Between October to March, it is recommended by Public Health England for everyone to supplement 10 mcg daily vitamin D supplement. Though some may need a higher dose than 10mcg (400 IU) a day. Those who are at higher risk of deficiency, such as people who are older than 65 years or stay indoors, those who have darker skin or wear clothing that covers skin as well as obese people, are recommended to take vitamin D all year around. Choose a vitamin D3 supplement for best absorption.
Vitamin B12 supplements
Obtaining vitamin B12 if you do not consume dairy milk products or are on a vegan diet can be difficult, so it is worth taking a blood test to check your vitamin B12 stores, and then considering a supplement. If you are recommended to take a vitamin B12 supplement, we recommend a daily dose of 25-100mcg of cyanocobalamin (form of vitamin B12) or a weekly dosage of 2,000mcg. Larger doses are unlikely to be as effective, as absorption in higher doses is poor.
Omega 3 fatty acid supplements
Although you can obtain omega 3 through nuts and seeds, the type of omega 3 found in these foods is not the best source for the body, as it needs to be converted from alpha-linolenic acid (ALA) to eicosapentaenoic acid (EPA) and eicosapentaenoic acid (DHA). However, the conversion rate is poor, which is why it is recommended for vegetarians and vegans to consume an algae based supplement, to ensure you are obtaining a good level of EPA and DHA.
Iron
Although iron is found in many plant food sources, it is found as non-haem iron, which is not as readily absorbed compared to animal sources known as haem iron. Therefore, certain populations can benefit from an iron supplement, to help ensure they are meeting their requirements. If you are vegan or vegetarian and a woman with a regular menstural cycle, it is likely that iron will benefit you further due to the monthly loss of blood and iron stores. We would recommend checking your iron level through a blood test before considering a supplement. Some supplements are tolerated well, however others can lead to side effects such as constipation and stomach aches, so it is best to speak to a health care professional to choose the best iron supplement for you.
Calcium
If you do not consume dairy milk, and you choose a non-fortified plant based milk alternative (e.g. an organic option), then you may need to consider calcium supplementation. Although you can obtain calcium sources on a vegan diet, levels can vary and you would need to be consuming at least 3 calcium rich foods per day to help you meet your requirements. Research has shown that those on a vegan diet are not meeting their calcium requirements and can be at increased risk of bone fractures.
Iodine
Although plants contain iodine, found from the soil from that they grow from, the total concentration is variable and can often be very low. There are no other rich iodine sources in a vegan diet. If you consume regular dairy products as a vegetarian, iodine supplementation is unlikely to be needed, as well as if you consume at least 500ml of plant milk, fortified with iodine, per day. However, if your diet is low/minimal in dairy and you do not consume fortified plant milk, it is worth considering an iodine supplement, or using iodised salt in cooking. However, too much iodine can be harmful for our thyroid health, so it is important to speak to your health professional team or a registered dietitian, for bespoke and tailored supplementation advice.
Strategies to enhance vitamin absorption
Here are tips on how to eat certain foods, to help with enhancing nutrient absorption from a vegan or vegetarian diet.
Nutrient combining:
Certain foods can be combined for consumption, which can aid the absorption of nutrients.
For example, when eating vegetarian or vegan sources of iron such as lentils or spinach, combine these with foods rich in vitamin C like lemon, peppers and potatoes, which can greatly enhance the absorption of the non-haem iron found in plant foods.
Not only does vitamin C help with iron absorption, but vitamin A also helps to release iron in the body. Sources of vitamin A such as carrots, kale, oranges and peaches are also great sources of vitamin C.
Calcium rich foods such as tofu and fortified dairy products, are better consumed alongside a source of vitamin D. This is because the vitamin D supports calcium absorption in the small intestine, and although there are not many great sources of vitamin D, dairy and plant based fortified milks contain both calcium and vitamin D, so are an ideal food to include regularly.
When consuming foods that are a good source of fat-soluble vitamins A, D, E and K, it helps to also consume healthy fats alongside them, such as avocado and nuts. This is because the fats are needed to help absorb the fat soluble nutrients. For example, when making a salad with plenty of sources of vitamin A and K, add in a sprinkle of nuts and seeds to boost the vitamin absorption.
Avoiding certain combinations:
As well as foods helping to support nutrient absorption, there are compounds found in certain foods which can reduce or block certain nutrient absorption.
Tannins, found in tea, coffee and wine, greatly reduce iron absorption, as the tannins bind to the iron and remove it from the body. Therefore, if you are someone who enjoys a caffeinated drink or glass of wine, try to avoid consuming these with a meal or within 30 minutes of a meal time, to minimise this influence.
There are compounds known as phytates, found in many plant foods including wholegrains, legumes, soy and seeds. These phytates reduce absorption of iron as well as magnesium, calcium and zinc. However, it is important to note that phytates have many health benefits associated, including supporting with the reduction of cholesterol and slowing digestion rates. Therefore, avoiding phytate containing foods is not the answer, but ensuring your diet is as varied as possible will help you get these less absorbed nutrients, from other sources. Soaking foods with phytates in can also reduce the overall concentration.
Similar to phytates, compounds known as lectins, also interfere with absorption of nutrients including calcium, iron, phosphorus and zinc. Lectins are found in legumes such as soy beans and chickpeas, lentils, as well as wholegrains and peanuts - all nutritious foods. But it is important to keep in mind that lectin is most potent when in raw foods, so cooking foods can greatly reduce lectin levels. Particularly high heat and wet methods of cooking like boiling. Soaking raw beans and lentils in water before cooking can inactivate much of the lectin levels, as it is water soluble.
Improve meal timing
Ensure that your main meals are spread across the day and are well balanced, to help your body with regular absorption and utilisation of nutrients. This also means you can plan meals to include a range of nutrients, to prevent any anti-nutrient factors, such as phytates and lectins, from having a major impact on overall nutrient status.
How to check your nutrient levels if you're on vegetarian or vegan diet?
The most effective ways to check your nutrient levels is through a blood test. This will measure the level of certain vitamins and minerals in your blood, which can give you in indication to if you are needing more of this nutrient, or your diet is adequate to meet your requirements. Certain nutrients can be commonly checked for in blood tests. These include:
- Vitamin B12: Important for the production of DNA, red blood cells and nerve function.
- Vitamin D: Key in immunity, inflammatory response, bone health, hormonal production and more.
- Iron: Needed to transport oxygen around the body in red blood cells, to prevent iron deficiency anaemia.
- Calcium: Helps to maintain density of bones, as well as important for muscle function.
- Iodine - Thyroid function: This will show if you have enough iodine in your body, as thyroid dysfunction can be linked to too little or too much iodine, such as a dysregulation in thyroid hormones known as T3, T4 and TSH.
A urine test can check for iodine levels, though a thyroid function test will provide more information.
Certain nutrients are not routinely measured in a blood test, so you will need to request specific tests for the following nutrients. This includes:
- Omega-3 Fatty Acids: This will look at your levels of different omega fatty acids, typically omega 3 and 6. Looking at the ratio of each fatty acid is important, as plant based diets generally contain more omega 6 fatty acids, compared to omega 3, but for optimal health we want a good ratio of both.
- Zinc: Testing for zinc levels is not in a routine blood test, and will need to be ordered specifically. Urine tests can also check for zinc, and it is crucial for DNA synthesis and immune function.
As well as a blood test, consulting with a dietitian can help you identify what nutrients you may be lacking, by interpreting blood test results and also suggesting ways to improve your diet, to reduce risk of certain deficiencies.
Home test kits are popular to check for nutrient levels, which often involve a finger prick blood test which is sent to the lab. It is important to use a reputable brand, and discuss your results with your GP or dietitian, to implement the recommendations safely.
How often to check your nutrient levels?
If you are switching to a vegetarian or vegan diet, it would be a good idea to establish a baseline of your nutrient levels, to be aware of any deficiencies you may already have, to ensure you implement the right dietary changes as soon as possible.
Following this, we would recommend a yearly blood test to check for nutrient levels, or 6 months if you have previously had a deficiency in any nutrients. Regular monitoring helps to ensure you can make the needed changes and to prevent mild deficiencies developing into moderate or severe deficiencies.
If you notice any unusual symptoms, this could be suggestive of a vitamin or mineral deficiency, so it would be advisable to get a blood test. These symptoms can include extreme fatigue, low mood, poor immune system, weak hair and nails, especially if you cannot identify any reason for these symptoms.
Myths about plant-based diets and vitamin deficiency
There are certain myths about vegetarian and vegan diets that can stem from misunderstandings and misinformation. Here are some common myths, and the real truth behind them:
- Plant based diets always lead to vitamin deficiencies
Although certain plant based diets can lack certain nutrients, if you plan well for your diet and include a range of vegetarian or vegan foods, deficiency is less likely. There may be certain foods that you will need to consume more frequently or in larger servings, and, depending on your diet, you may need to supplement with some nutrients. - You cannot obtain a good level of iron on a vegan diet
Iron from food is found as haem and non-haem iron. Haem iron is found in animal products and is readily absorbed, however non haem iron is found in plant foods such as lentils, beans, soy and greens. Although non haem iron is poorly absorbed compared to haem iron, if you consume foods rich in vitamin C alongside these plant based iron sources, this will greatly improve the absorption of the haem iron, as explained above.
- You cannot get enough calcium on a vegan diet
There are a range of great calcium sources in a plant diet, including soy products such as tofu, fortified plant milks, seeds such as chia and sesame seeds, and leafy greens like kale. Although the bioavailability of calcium from these plant sources is lower, regular consumption of these foods will help to meet your calcium requirements. - You cannot get enough omega 3 fatty acids on a vegan diet
Although oily fish are the highest source of omega 3 fatty acids, in the diet, you can also obtain these from plant foods. There are various types of omega 3 fatty acids, including EPA, DHA and ALA. ALA is the type of fatty acid found in plant foods such as walnuts, chia seeds, flax seeds, hemp seeds, as well as algae supplements. ALA needs to be converted into EPA and DHA in the body, though this conversion rate is low. However, if you follow a vegetarian and vegan diet, we would recommend an algae based supplement, to ensure you are obtaining a good level of EPA and DHA. - You cannot obtain vitamin B12 on a vegan diet
Whilst it is true that animal products such as dairy, eggs, meat and fish naturally contain vitamin B12, it can still be obtained from a vegan diet. This means including fortified foods, including plant milks, fortified nutritional yeast and breakfast cereals, which all have vitamin B12 added. However, we would still recommend for most following a vegan diet to supplement with B12, especially if your intake of fortified foods is low and infrequent. - The immune system of a vegan or vegetarian person is not as effective
Making sure your vegan or vegetarian diet is rich in foods such as fruits, vegetables, grains, nuts and seeds will ensure you have a diverse intake of vitamins, minerals, antioxidants and immune supporting nutrients. Therefore, planning is key to help ensure your diet is varied, to support your immune function. - Dietary supplements do not work
Supplements play a crucial role in helping people meet their bodies requirements of certain nutrients, especially a select few nutrients which are much harder to obtain on a vegan diet, such as omega 3 and vitamin B12. We should not rely too heavily on supplements and try to obtain nutrients through diet first, however, in some cases, supplementation may be necessary. It is important to choose a good quality supplement to ensure you are getting the dose of nutrient as stated.
Having support from a dietitian can help you ensure your vegetarian or vegan diet is balanced and you are not missing out on key nutrients, as well as helping you plan a sustainable lifestyle and routine with eating. Book a consultation with a dietitian here.