A vegan diet is one that consists of only plant-based foods. It not only avoids meat, but also the consumption of eggs and milk (dairy products too).
Since these foods are rich in nutrients, specifically- calcium, iron, vitamin D and Vitamin B12, it is important to strengthen the diet accordingly with healthy plant-based foods.
Vitamin B12 is a key nutrient that is important for various bodily functions. Vitamin B12 helps in the formation of new red blood cells, DNA synthesis and nerve health. This nutrient helps in the synthesis of myelin which is what coats the nerve fibres and is important for transmitting electrical impulses to the body. In addition, this vitamin helps in biochemical reactions that involve the production of DNA, RNA, protein and fat (which provide energy for the body when broken down for use).
A lack of this nutrient can cause health problems that range from megaloblastic anaemia to fatigue and loss of appetite. Since B12 is involved in neural health, this can also cause neurological symptoms which cause confusion, tingling of hands and feet, numbness, depression and memory loss.
Those who follow a vegan pattern of eating, need to ensure that their diets are well planned and also contain the required supplements needed to maintain good health. This ranges across all age groups who follow a vegan diet. In a study, Rizzo et al., encourages older people following a vegan diet to include Vitamin B12 supplements. This is important since in the elderly, there could be age related digestive changes making it harder to synthesize cobalamin proteins. The gastric juices play a key role here as they help absorb cobalamin from foods while also binding it to a carrier so that it can be effectively utilized in the body.
Animal foods contain vitamin B12 in its most active and ready to use form. Although plant-based foods contain some amount of vitamin B12, the processing and cooking methods or even pasteurization can cause a loss of this important nutrient.
Can a plant-based diet support vitamin B12 requirements?
Plants are not reliable sources of B12 since they themselves do not depend on, or need this nutrient for their functioning. They have nowhere to store or produce it which then makes them poor sources. Produce that contains soil on it is still very low on vitamin B12, again this needs to be washed and cooked which further reduces the nutrients’ presence. Sea based foods like seaweed may have a small amount of B12, but this is again due to the cobalamin bacteria which is minimal. Eating in this way could be healthy for other reasons, but should culminate in effective supplementation. Low vitamin B12 levels could lead to elevated levels of homocysteine which negatively affects heart health.
Next steps
Vegetarians and vegans should routinely screen for nutrients like vitamin D, iron and vitamin B12 to rule out any possible deficiencies. Pregnant or lactating women in this category need to take 250 mcg supplement. However, any supplements should be taken on the recommendation of a doctor. This is higher than the RDA, but is often recommended, since only 1% of the total amount is actually absorbed.
Intramuscular injections can help treat dietary deficiencies and deficiencies caused due to malabsorption as in the case of pernicious anemia. These doses must be regulated and taken on the advice of a medical practitioner. High doses of intramuscular vitamin B12 can lead to a flare up of acne rosacea. It could also worsen kidney function in those with diabetic nephropathy.
Sources of Vitamin B12 from a vegan and vegetarian diet
Though these sources are limited, those following veganism or vegetarianism can include these foods in their diet. But always take a supplement/ injection only as prescribed by your doctor.
References Debunking the Myth – Vegans and Vitamin B12. (2019). Retrieved from https://www.veganlifemag.com/debunking-myth-vegans-vitamin-b12/ Natalie Butler, L. (2019). Vitamin B-12 foods for vegetarians and vegans. Retrieved from https://www.medicalnewstoday.com/articles/320524.php The vegan diet. (2019). Retrieved from https://www.nhs.uk/live-well/eat-well/the-vegan-diet/ Vitamin B12 and the Vegan Diet - Today's Dietitian Magazine. (2019). Retrieved from https://www.todaysdietitian.com/newarchives/0418p38.shtml What Every Vegan Should Know About Vitamin B12. (2019). Retrieved from https://www.vegansociety.com/resources/nutrition-and-health/nutrients/vitamin-b12/what-every-vegan-should-know-about-vitamin-b12 Rizzo, G., Laganà, A. S., Rapisarda, A. M., La Ferrera, G. M., Buscema, M., Rossetti, P., … Vitale, S. G. (2016). Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients, 8(12), 767. doi:10.3390/nu8120767