Vitamin B12 for Vegans: Dr Justine Butler from Viva! Health debunks the myths surrounding this vital vitamin
It’s a myth that vegans need to take handfuls of supplements in order to stay healthy. Of course, everyone needs to ensure they’re getting a good supply of vitamin B12, regardless of diet – and during the winter months, everyone in the UK should consider taking vitamin D. Other than that, a varied vegan diet will supply all you need to lower your risk of disease and help you live a long, healthy life.
All the B vitamins help our bodies produce energy from the food we eat. Vitamin B12 also helps maintain healthy nerve cells and produce DNA – our genetic material. It works closely with folic acid to make red blood cells, which helps iron to work more efficiently in our bodies. It contributes to the production of compounds that help our immune systems function normally and can even affect our mood.
Signs of deficiency include extreme tiredness, lack of energy, pins and needles, muscle weakness, depression and cognitive problems such as impaired memory, understanding and judgement. Anaemia can occur when a lack of B12 (or folate) affects your body’s ability to produce enough red blood cells – it can also lead to a raised blood level of the amino acid homocysteine, which has been linked to heart disease.
If you’re concerned about your own B12 levels, visit a doctor and asked to be checked – any deficiencies can be treated with supplements or a course of injections. The truth is, we only need a little B12, with UK guidelines recommending 1.5 micrograms a day – a microgram is a millionth of a gram – but getting that small amount is vital. US guidelines are slightly higher at 2.4 micrograms and the European Food Safety Authority (EFSA) suggest an ‘adequate intake’ of 4.0 micrograms a day.
The unknown truth
Media scare-stories have focused on a very limited number of ill-informed ‘vegans’ who have been found to be deficient in B12. However, UK National Diet and Nutrition Surveys have found evidence of low vitamin B12 status in teenagers and adults regardless of diet, so meat-eating is not a panacea.
Low levels are not uncommon in the UK, especially in people over 50, because absorption is a complicated process that declines with age. In order for B12 to be absorbed, it must first bind with a protein produced in the stomach called intrinsic factor. If you don’t make enough, you may not be able to absorb enough B12, even if your diet contains plenty.
Another reason absorption declines with age is because the amount of stomach acid we make can drop as we get older. B12 from meat is bound to animal protein, so stomach acid is required to release it before it can be absorbed. B12 in fortified foods and supplements is not bound in this way and so is easier to absorb.
Absorption can also be reduced by poor functioning kidneys, by the diabetes drug Metformin and proton pump inhibitors, nitric oxide in cigarette smoke and nitrous oxide (laughing gas) – now a popular clubbing drug.
Sources of B12
B12 is made by bacteria in soil and water and to some extent bacteria in the gut although production occurs in a different area to where absorption takes place. Traditionally, people and animals would have got their B12 from eating food from the ground and from well water. However, now food production systems are so sanitised, we need to take a supplement. Animals are no different, with meat, eggs and dairy foods containing vitamin B12 only because farmed animals are given a supplement, too.
Around 80 per cent of global production of B12 is in France and over half of it is used to supplement animal feed. This makes the recommendation to eat animal products to obtain your B12 somewhat invalid – cut out the middleman and get B12 straight from the source.
Whether you choose fortified foods or supplements, you need to consume these regularly. There’s no need to take extra-high doses but if you do, government guidelines say that taking up to 2,000 micrograms a day is unlikely to cause any harm. It’s a water-soluble vitamin, so what you don’t use or need is excreted in your urine.
Understanding the options
The two main forms of vitamin B12 are cyanocobalamin and methylcobalamin. Cyanocobalamin is a cheap and stable form used in most fortified foods and supplements and as long as you’re healthy, it’s perfectly suitable. Methylcobalamin is an ‘active’ form that costs more as it’s not so stable and is recommended for smokers and people with kidney problems.
B12 can be lost in cooking. For example, if you heat B12-fortified plant-based milk in a microwave, B12 may be destroyed in a couple of minutes. However, when cooked on the hob or steaming, the milk would have to be at, or near, boiling point for five to seven minutes to destroy a significant amount of B12. So, the traditional approach is better!
Best plant sources of vitamin B12 are manufactured products that have been fortified – yeast extract (Marmite/Vegemite), nutritional yeast flakes, plant-based milks, yoghurts and desserts, breakfast cereals and margarines. Check the labels to ensure you are buying the fortified versions. Fermented soya foods and seaweeds don’t provide a reliable source of B12.
B12 can be stored in the body for two to four years without being replenished, so it can take a long time for any problems to develop after a dietary change. However, you should not rely on your stores of B12 as there’s no guarantee you’ll have enough – plus, it’s always better to be safe than sorry!
So, should you take a supplement? Yes! Viva! Health recommends an intake of 5.0 micrograms per day from fortified foods with the regular use of supplements to ensure this level is topped up. This is particularly important for children.
Mild to moderate B12 deficiency is not uncommon in industrialised countries despite the fact that that a typical western, meaty diet provides around 5-7 micrograms of B12 a day. Up to 40 per cent of older people in the UK suffer from low B12 because of impaired absorption and as most meat is consumed after cooking, there are further losses of B12. This is recognised in the US with all adults over 50 being advised to get B12 from supplements or fortified foods because of the high incidence of reduced absorption from animal foods. Vegans have a head start if they routinely include fortified foods and supplements in their diet.
A well-planned and varied vegan diet, including B12-fortified foods with a regular B12 supplement, will meet your requirements and provide a healthier and safer source of vitamin B12.
• Dr Justine Butler from Viva! Health, part of the vegan charity Viva!. Viva! Health monitor scientific research linking diet to health and provide accurate information on which you can make informed choices about the food you eat, vivahealth.org.uk
Try our recipe for B12 cheese – one serving contains the recommended daily allowance