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  • Writer's pictureCaitlin O’Nions

The Importance of B12 in a Plant-Based Diet

Updated: Jun 15, 2022

Vitamin B12 (also known as Cobalamin) is a water-soluble vitamin, and is essential in a number of bodily processes such as the formation of red blood cells and the transcription of DNA.

You can find vitamin B12 in animal foods such as fish, red meat, eggs and poultry. It is also found in yeast extract and fortified products such as breakfast cereals, dairy products and nutritional yeast. Essentially, those following a vegetarian or vegan diet have a much narrower range of choices when it comes to foods containing B12, meaning extra planning is needed!


A lack of B12 exhibits itself in a number of ways, and a simple blood test may not be enough to diagnose a deficiency. Biomarkers such as methylmalonic acid and homocysteine are considered better indicators and both increase with a B12 deficiency. A lack of Vitamin B12 or folate over a prolonged amount of time can also lead to anaemia. Certain groups, such as those with digestive disorders, may be more likely to develop a deficiency since B12 is absorbed in the very last part of the small bowel called the Terminal Ileum. For that reason, anyone who has had surgery on their bowel is at risk of B12 deficiency. In fact, 31% of people who have had stoma formation will develop B12 deficiency.

Warning signs of a B12 deficiency

Those with a vitamin B12 deficiency may experience:

  • Rapid heartbeat

  • Tingling sensation in the hands and/or feet

  • Dizziness

  • Headaches

  • A sore and swollen tongue

  • Fatigue

If left untreated, some symptoms of vitamin B12 deficiency may be irreversible. For this reason, it’s important to seek help from your GP if you suspect a B12 deficiency. As the body can store B12 without being replenished for around 2-4 years, any signs of deficiency can develop really slowly and can be hard to spot. This means it can also take a while after any dietary changes to identify a possible deficiency.

Vitamin B12 & Plant-Based Diets

As Vitamin B12 is only found naturally in animal products, it can be tricky to consume enough on a strict vegan or vegetarian diet.

Consequentially, it is recommended that those following plant-based diets should consume ample quantities of foods fortified with Vitamin B12 and/or consider taking a daily supplement to ensure deficiency does not occur. Nearly all vegan & vegetarian health bodies recommend supplementation, but be sure to contact your GP or seek advice from a dietitian first.

Other foods commonly found in a plant-based diet, such as tofu and tempeh, contain components similar to Vitamin B12 but don’t quite react the same in the body. Therefore, these foods can't be solely relied upon for adequate intake. Fortified products such as cereals and dairy products may have health claims or statements such as ‘with added B12’ on the packaging. The added Vitamin B12 will always be listed in the nutritional breakdown table if it is present so you can check the label for confirmation.

Adults need about 1.5 micrograms of vitamin B12 a day according to the NHS, so make sure if you are looking to take a supplement, that the dosage will meet the daily requirement.

Though Vitamin B12 deficiency is most commonly associated with plant-based diets, there are other groups at high risk. Our absorption of B12 also declines with age, meaning it is not uncommon to find B12 deficiency across the general population regardless of meat intake, according to the UK National Diet and Nutrition Survey.

The take-home message is that it is definitely possible for veggies and vegans to get plenty of vitamin B12 in the diet, but it will just take some strategic planning!

A dietitian can provide you with advice and guidance for planning a balanced diet that meets your nutrient needs. Learn more about our dietitian services for vegetarians and vegans.



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