Nutritionist Rishi Kumar Nursimloo reports for Vegan Life on the importance of vitamin B12.
In comparison to meat-based diets, a vegan diet is lower in saturated fat, calories and contains more fibre and phytonutrients/phytochemicals, which have been shown to have protective properties in association with lower risks of certain cancers, cardiovascular disease, obesity, type 2 diabetes, high blood pressure and lower levels of cholesterol.
However, there is cause for concern surrounding the availability of vitamin B12 in a vegan diet.
What is vitamin B12?
Vitamin B12 (or cobalamin) is a water soluble vitamin stored in the muscle and liver, which has vital roles such as DNA synthesis, producing healthy red blood cells in the bone marrow, as well as maintenance of your peripheral and central nervous system, such as the brain, spinal cord and nerves.
It is wrongly assumed that since B12 is stored in muscles of meat, that this is the only way of consuming this vital vitamin. In fact, B12 is produced by bacteria in the soil and therefore is not directly produced by animals or plants — B12 bio accumulates within animals and plants and is therefore found in its greatest quantities in meat. Further, due to modern day soil-farming practices, there has been a steep reduction in the amount of B12, and consequentially within plants, which makes it harder to obtain B12 through diet.
Therefore, it is imperative that vegetarians and vegans are careful about maintaining adequate levels of B12 to ensure overall health.
Why is B12 so important?
One cause of deficiency is through diet. Studies have found that it takes between three and ten years to be deficient in B12 and therefore it’s a more abstract health concern for some compared to more visible deficiencies such as iron. This does not make it less important.
Chronic B12 deficiency can lead to anaemia as well as increased levels of both amino acid homocysteine and methylmalonic acid in the urine and blood. There is an increasing body of evidence that supports that elevations of these two acids can heighten the risk of heart disease, preeclampsia (a pregnancy related condition which can cause severe complications to mother and baby), neural tube defects in babies and the development of neurodegenerative diseases, such as Alzheimer’s, Parkinson’s and risk of bone fractures.
Another consequence of vitamin deficiency is pernicious anaemia, a common condition in the UK which arises from inadequate amounts of B12. This is due to a lack of a protein called intrinsic factor, which is required for the binding and absorption of B12 in the cells of the gastrointestinal tract, more specially the small intestine. Without this protein (or as it decreases) the body’s ability to absorb B12 is radically reduced and can even stop completely.
It is also important to understand that other factors such as surgical removal of the stomach and certain other health conditions can also cause you to stop creating intrinsic factor and absorbing B12. Other types of anaemia, such as anaemia as a result of a lack of folic acid, can exhibit similar symptoms to B12 deficiency, so please see your GP or healthcare provider if you are on a vegan diet and have concerns.
Should you supplement?
Whether you choose to supplement or consume through diet, it is essential you keep a few things in mind. Most foods with high levels of B12 are fortified as the natural occurrence of the vitamin is so scarce. Also, the availability and amount of B12 varies from brand to brand, so taking time to read the label foods will ensure you are meeting the Nutritional Reference Value (NRV).
Common fortified foods which contain B12 include:
- Fortified yeast
- Fortified soya milk
- Fortified breakfast cereals
- Certain brands of rice drinks and oat drinks – Not only have Alpro introduced fortified plant based milks for adults, but also for toddlers aged 1-3+
Another way to ensure you are getting the correct intake of B12 is through supplementation. There are different types of B12 that are offered (non-prescribed) such as cyanocobalamin, methylcobalamin and adenosylcobalamin. However, cyanocobalamin is recommended due to its higher stability when broken down and therefore its increased bioavailability in the body.
To date, there are no maximum intakes set for B12 and there seems to be no evidence to show toxicity or adverse side effects when consuming high amounts of the vitamin.
Despite this, it is simply not necessary to exceed the NRV, which is recommended at 2.5ug a day. If you are considering supplementing your diet with B12 make sure you talk to a health professional
Plant-based diets are both delicious and nutritious but can lack the necessary amount of B12 needed to maintain proper health. Luckily, overcoming this deficiency can be easily rectified; it is recommended that vegans take a daily B12 supplement.
Both the American Dietetic Association and Dietitians of Canada have stated a well-planned vegan diets are appropriate for all stages of the life which includes during pregnancy, lactation, infancy, childhood, and adolescence. In the United Kingdom, both The Vegan Society and the British Dietetic Association have collaborated in order to bring the best evidence-based practice in plant-based nutrition to medical professionals, service providers and clients to every community in the UK.
The current trend and support towards plant-based nutrition is constantly growing and due to this movement, food industries are adapting to this change, producing a plethora of meat, egg and dairy alternatives, many of which are fortified with B12.
If you do have any concerns regarding your B12 intake, please see a nutritionist or dietician.