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How to get all essential nutrients on a vegan diet

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

6 min read
Last updated June 2024

Jump to: Are vegan diets nutritionally adequate? | Nutrients, vitamins, and minerals of concern | Improving bioavailability | Supplementation and fortified foods

The vegan diet is an entirely plant-based diet that eradicates the consumption of all animal products, including eggs and dairy, and some foods made from the use of animals like honey.

While vegan diets have been shown to have health benefits due to the higher consumption of fruits, vegetables, and fibre compared to people eating a typical Western diet, there are concerns about whether the diet can provide all of the essential nutrients your body needs.

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Are vegan diets nutritionally adequate?

Objectively, the short answer is no. There are specific vitamins, minerals, and nutrients that you can only obtain from animal sources, such as vitamin B12. Due to anti-nutrients in plant foods, there are also issues with digestibility and absorption of minerals such as calcium and iron.

However, this doesn’t mean you can’t be healthy on a vegan diet. But it does mean that a vegan diet needs more planning than a diet containing animal products.

Having a varied diet with the addition of fortified foods and supplementation can ensure you’re providing your body with everything it needs to thrive.

At Second Nature, we’re not here to judge you for what diet you choose to follow. Your diet is a personal choice, and we’re here to support you every step of the way.

You can join people like Sarah who’ve joined our programme and changed their minds about healthy living to make weight loss feel easier while eating a plant-based diet. All you need to do to start is click here to take our health quiz.

Otherwise, keep reading as we provide you with three evidence-backed ways you can ensure you’re getting all of the essential nutrients you need to achieve good health.

1) Nutrients, vitamins, and minerals of concern

Below, we’ve compiled a table of the nutrients, vitamins, and minerals you should pay close attention to on a vegan diet, their functions, and where you can source them.

You may need to scroll down the table to see the full image. 

Vitamin, mineral, or nutrient Function and background Sources Supplementation recommended?
Vitamin B12 B12 is an essential water-soluble vitamin with essential functions, including developing the central nervous system and maintaining healthy red blood cells.

The liver can store up to 5 years of B12, so deficiency may not become clinically apparent for many years after starting a vegan diet.

Deficiency is linked to a range of conditions from depression and nerve problems.
No plant-based sources


Fortified foods such as nutritional yeast

Vitamin K2-MK7 K2-MK7 is a fat-soluble vitamin with essential roles in the cardiovascular system; it also supports vitamin D in maintaining adequate bone health.

Deficiency may lead to issues with blood clotting and increase the risk of osteoporosis.
Natto and other fermented plant foods like sauerkraut and kombucha


Yes, if you’re not consuming enough fermented plant foods
Omega-3s: EPA/DHA EPA and DHA are long-chain polyunsaturated fatty acids.

They’re classed as essential as the body can’t make them, and the conversion of the plant-based omega-3, AHA, is very low (between 1-10%). 
They have essential bodily functions, such as forming part of our cell membranes to reduce inflammation and support the brain’s function. (Around 25% of the fat content in the brain is DHA.)


Yes, if you’re not consuming algae regularly
Iron Essential for the healthy functioning of our red blood cells and the ability to transport oxygen around the body. 

Deficiency leads to anaemia which can lead to fatigue and heart palpitations.

While readily available in plant-based foods, non-heam iron is not as bioavailable as heam iron found in animal products.

Anti-nutrients found in some plant foods also inhibit their absorption.

Green leafy vegetables 




Fortified foods

Possibly, check with GP
Iodine An essential component of thyroid hormones T3 and T4, which have essential roles in our metabolism. 

Deficiency can lead to goitre, an enlarged thyroid gland, and impact metabolism.

Cereals and grains that are grown closer to the sea

Fortified foods (iodised salt) 


Possibly, check with GP
Calcium Essential for healthy bones, muscle contractions, and blood clotting. 

While present in many plant foods, the issue comes with bioavailability as anti-nutrients inhibit absorption.

Green leafy vegetables 

Lentils and legumes 

Fortified foods 


Possibly, check with GP
Protein Plant-based proteins tend to be limited by specific amino acids, which inhibit their ability to promote adequate growth and maintenance of cells.

They’re also less bioavailable than animal proteins due to the structures of the plant cell walls.

Click here to read more about vegan protein sources and how to maximise your protein intake on a vegan diet.



Lentils and legumes

Nuts and seeds

Protein powders

Protein powders may need to be considered
Click here to find a list of healthy vegan recipes.

2) Improving bioavailability

An issue with some plant-based foods is they contain some anti-nutrients which inhibit the absorption of essential minerals. For example, lentils are a source of non-heam iron but also contain phytic acid (phytates), which inhibits iron absorption in the gut.

However, cooking, milling, soaking, and fermentation have all been shown to reduce anti-nutrient content and increase the bioavailability of minerals such as iron and calcium.

For example, a study showed a significant reduction in phytic acid content in lentils after soaking and cooking. Similarly, another study showed that soaking chickpeas for up to 12 hours reduced phytic acid content by up to 55%.

Foods can also be paired together to increase the bioavailability of different minerals and nutrients. For example, consuming vitamin C helps to increase the absorption of non-heam iron and pairing different sources of proteins can ensure you meet your essential amino acid requirements.

Second Nature top tips:

  • Steaming or blanching green leafy vegetables, like spinach and kale, can increase the bioavailability of iron and calcium.
  • Avoid drinking tea and coffee with meals, the tannins inhibit iron absorption, and caffeine can inhibit calcium absorption.
  • Use iodised salt.
  • Soak beans, chickpeas, or lentils for 12-24 hours before cooking. You can also buy jars of beans, chickpeas, and lentils which would have already been cooked and soaked.
  • Try fermenting your own foods; there’s a great guide here.
  • Avoid consuming too many raw whole vegetables; these are more difficult for our body to digest, inhibiting the absorption of vital nutrients. However, consuming raw vegetables is still a better option than refined-carbohydrates and sugars, so it’s all about balance.
  • When you enjoy more raw salads, try grating vegetables like carrots, beetroots, and courgettes, or try warm salads.
  • Consume sources of vitamin C (peppers, tomatoes, strawberries, potatoes, broccoli, citrus fruit) in your meals to support the absorption of non-heam iron in foods like spinach and kale.
  • Ensure you’re pairing different sources of proteins to ensure adequate amino acid consumption.

3) Supplementation and fortified foods

As mentioned above, deficiencies can take years to become clinically apparent, and prevention is better than treatment. So we’d recommend supplementing the vitamins listed below or a daily multivitamin and mineral supplement to help cover your bases.

One issue with supplementation is that many off-the-shelf supplements can be of questionable quality. It’s worth investing in independently analysed and certified supplements to guarantee the quality of the product.

Fortified foods such as plant-based yoghurts, milk alternatives, and cereals can help you meet specific vitamins and minerals like B12, iron, and calcium requirements.

It’s best to check the packaging to see if the foods you’re buying provide you with what you need, as some milk alternatives are fortified with calcium and B12 while others aren’t.

Essential supplementation for vegans:

  • Vitamin B12: 50-100micrograms daily

Non-essential but potentially required supplementation for vegans:

  • Vitamin K2-MK7 (if not consuming fermented foods regularly): 200-300 micrograms daily
  • Omega-3s EPA/DHA (if not consuming algae regularly): 1000mg daily of combined EPA/DHA, this is typically found in an algae oil solution
  • Iron: 30-45mg daily
  • Iodine: 150 micrograms daily
  • Calcium: 1000-2000mg daily
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