As the vegan lifestyle gains more popularity worldwide, understanding essential nutrients becomes increasingly important. Vitamin B12, also known as cobalamin, is a crucial water-soluble vitamin that plays a significant role in red blood cell formation, DNA synthesis, and neurological function.1 Unlike many vitamins, vitamin B12 is predominantly found in animal products and dairy products, making it a critical focus for those following a plant-based diet as up to 52% of vegans may have a B12 deficiency compared to only about 1% of omnivores.2 This stark contrast highlights the necessity for vegans to be vigilant about their vitamin B12 intake to prevent potential health issues associated with B12 deficiency.
Those following the vegan diet run the risk of several nutrient gaps, including omega-3 fatty acid and calcium deficiency; in this article, we will delve into the importance of vitamin B12, the signs and risks of deficiency, and tips for meeting recommended intake on a vegan diet.
What Are the Roles of Vitamin B12 in the Body?
Red Blood Cell Formation
Vitamin B12 is necessary for the proper maturation of red blood cells in the bone marrow.1 A deficiency can disrupt this process and lead to a condition called megaloblastic anemia, characterized by abnormally large red blood cells that cannot function properly.3
Neurological Function
Vitamin B12 plays a significant role in maintaining the health of nerve cells and producing myelin sheath, which is the insulating layer composed of lipids and protein that protects nerves and ensures efficient transmission of nerve impulses.1
DNA Synthesis
Vitamin B12 is one of the many puzzle pieces that goes into DNA synthesis. B12 acts as a cofactor for the enzyme methionine synthase, which is essential for the conversion of homocysteine to methionine.4 This process is vital for the production of S-adenosylmethionine (SAME), a compound involved in the methylation of DNA, RNA, and proteins–thereby supporting cell division and growth.4
What Are the Vitamin B12 Deficiency Symptoms?
Vegans can experience several nutrient deficiencies due to their specific diet, and vitamin B12 deficiency is relatively common among vegans due to the lack of natural plant-based sources. Symptoms of deficiency can be subtle at first but may become severe over time.5 Common symptoms include fatigue, muscle weakness, constipation, loss of appetite, burning sensation of the tongue, and other nervous system issues such as numbness and tingling in the hands and feet, difficulty maintaining balance, and cognitive disturbances like memory loss and confusion.1,5
How to Meet Recommended Intake Vitamin B12 on a Vegan Diet
For vegans, it is important to seek alternative sources of vitamin B12 to avoid deficiency and reap its many health benefits. Here are some effective strategies:
Vitamin B12-Fortified Food Sources
Many plant-based foods are fortified with vitamin B12, as plant-based foods do not naturally contain vitamin B12. These vegan sources include breakfast cereals, plant milks, soy products (such as soy milk, tofu, and tempeh), and nutritional yeast.4 Regular consumption of these foods can help maintain recommended vitamin B12 levels.
Quick tip: We love tossing tofu seasoned with herbs and nutritional yeast in the air-fryer for a vitamin B12-rich and nutritious snack!
Vitamin B12 Supplements
Vitamin B12 supplements are widely available in various forms, including cyanocobalamin and methylcobalamin as the more common types.4 These supplements come in various preparations including tablets, sublingual (under-the-tongue) preparations, and sprays.4 It is often recommended for vegans to take a vitamin B12 supplement to fill gaps in the diet.
Vitamin B12 Injections
In cases of severe deficiency, or for those who have difficulty absorbing vitamin B12 from oral supplements, intramuscular vitamin B12 injections can be administered by a healthcare professional.4 These injections bypass the digestive system, providing immediate and direct absorption.4,5
What Is the Recommended Daily Allowance (RDA) of Vitamin B12?
The recommended daily allowance (RDA) of vitamin B12 varies by age; however, for most adults, it is about 2.4 micrograms (mcg) per day.1 Pregnant women, breastfeeding women, and older adults may require slightly higher amounts.1 Since the body can store B12 for several years, regular but modest supplementation or consumption of fortified foods is often sufficient.
If you are considering the vegan diet or are already following it, consult with a healthcare professional about your vitamin B12 status and personalized guidance.
Summary
Vitamin B12 is an essential nutrient that requires careful attention, particularly for those following a vegan diet. Although vitamin B12 deficiency is a valid concern, fortified vegan foods (such as nutritional yeast and breakfast cereals) and vitamin B12 supplements can provide enough vitamin B12 to maintain recommended levels. By taking these proactive steps, vegans can enjoy the numerous benefits of their diet without the stress of compromising their health.
If you enjoyed this blog, you may also like these:
Navigating Nutrient Deficiencies in the Vegan Diet: What You Need to Know
Omega-3 Fatty Acids and the Vegan Diet
Calci-Yum: How to Get Calcium on the Vegan Diet
Your Complete Vegan Guide to Digestive Enzymes
3 Supplements to Optimize Your Vegan Diet*
References:
1. National Institute of Health, Vitamin B12 https://ods.od.nih.gov/factsheets/vitaminb12-healthprofessional/.
2. Fernandes S et al. Nutrients. 2024;16(10):1442.
3. O'Leary F et al. Nutrients. 2010;2(3):299-316.
4. Güitrón Leal CE et al. Cochrane Database Systematic Review. 2022;2022(11):CD015264.
5. Langan RC et al. American Family Physician. 2017;96(6):384-389.
