With a growing shift towards vegetarianism and veganism, two questions are commonly asked: Am I getting all the nutrients my body needs? Does my diet support all essential biochemical processes?

These are extremely important questions and questions that should be considered by everyone, no matter what your personal food choices or individual dietary preferences. Understanding the essentials of nutrition and the key roles that vitamins and minerals play within the body helps us make informed nutritional decisions, so we can adequately nourish our bodies with the building blocks of life.

Of particular importance is Vitamin B12. This is an essential nutrient involved in numerous physiological processes, including DNA synthesis^1,2; the metabolism of carbohydrates, fats and proteins¹; the maintenance and integrity of myelin in nerve cells³; normal nervous system function²; proper red blood cell formation⁴; normal growth and development⁴; and the remethylation of homocysteine to methionine.²

Common signs of B12 deficiency include fatigue, peripheral neuropathy, macrocytic anaemia (abnormally enlarged red blood cells), depression, confusion, angular stomatitis, constipation and skin hyper pigmentation.^2,4

Why you need Vitamin B12 (and why a vegan diet is unlikely to provide enough)

As Vitamin B12 is produced by microbial synthesis in the digestive tract of animals¹, plant based diets alone rarely contain this vitamin in adequate quantities.² This means vegetarians may be at risk of vitamin B12 deficiency and strict vegan diets are almost certainly not providing enough.³ Although algae and mushrooms are often promoted as substitute sources for Vitamin B12, they provide negligible quantities or contain inactive analogues, resulting in insufficient intake to sustain all necessary biochemical functions.³

A recent systematic review investigating the effects of vegan and vegetarian diets during pregnancy, reported that pregnant vegan and vegetarian women have an increased risk of developing vitamin B12 deficiency, with the authors concluding that particular attention should be paid to ensuring sufficient nutrient intake.⁵ Additionally, a depleted status among vegetarian women has been reported to impact neurodevelopment in infants, affect normal growth rate and be involved in irritability and refusal of solid foods⁶, further highlighting the importance of sufficient intake among these population groups.

As a vegan or vegetarian, how can I ensure I am getting enough Vitamin B12?

For those following a vegetarian or vegan diet, the best way to ensure suitable B12 intake is through supplementation of this vitamin. This can be done through fortified foods such as some grains, milk alternatives or cereals (check the labels), or otherwise a good quality vitamin B12 supplement. I suggest that if you are concerned that you are not consuming enough, talk to your healthcare professional for suitable recommendations.

As deficiency signs often don’t manifest for years, it can be a common misconception that the diet is supplying a sufficient quantity of this nutrient so no supplementation or action is taken. The problem is however, that once stores reach deficient levels, symptoms such as myelin degeneration (deterioration of the nerves) may be irreversible.² Although a plant based diet offers a range of significant health benefits, such as a reduction in the risk of coronary heart disease, certain cancers and Type 2 Diabetes, the implication of nutritional deficiencies can out way these highly desirable health benefits.²

When choosing to adopt a vegetarian or vegan diet, it’s important to ensure adequate amounts of all essential nutrients are being consumed. Conscious eating is a great thing, but just as important is a balanced and nutritionally sound diet, which provides all the necessary building blocks for the body’s essential biochemical processes.

So are you getting all the nutrients your body needs? Does your diet support all essential biochemical processes?

References & Further Reading

1. GlobinMed. Vitamin B12. Global Information Hub On Integrated Medicine. http://www.globinmed.com/index.php?option=com_content&view=article&id=78240:vitamin-b12&catid=18&Itemid=157. Published 2015.
2. Rizzo G, Laganà AS, Rapisarda AMC, et al. Vitamin B12 among vegetarians: Status, assessment and supplementation. Nutrients. 2016;8(12). doi:10.3390/nu8120767.
3. Silva S, Pinho J, Borges C, Santos C, Santos A, Graca P. Guidelines for a Healthy Vegetarian Diet.; 2015.
4. National institute of Health Office of Dietary Supplements. Vitamin B12 — Health Professional Fact Sheet. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/. Published 2016.
5. Piccoli GB, Clari R, Vigotti FN, et al. Vegan-vegetarian diets in pregnancy: Danger or panacea? A systematic narrative review. BJOG An Int J Obstet Gynaecol. 2015;122(5):623-633. doi:10.1111/1471-0528.13280.
6. Dror DK, Allen LH. Effect of vitamin B12 deficiency on neurodevelopment in infants: Current knowledge and possible mechanisms. Nutr Rev. 2008;66(5):250-255. doi:10.1111/j.1753-4887.2008.00031.x.

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