Balancing Act: Maintaining Optimal Vitamin B12 Across Dietary Patterns

A discussion about B12 supplementation, its provenance, and findings from a 2023 study comparing the vitamin status in omnivorous, vegetarians, and vegans.

Takeaways

• Microorganisms produce B12

• Omnivores and vegans had similar B12 levels, while vegetarians had a poorer status

• Vegans understand their supplementation needs

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💊 I recently researched B12 supplementation to determine whether I am taking reasonable measures as I primarily follow a plant-based diet. I realized that navigating the daily dose recommendations can be confusing. For instance, the European Food and Safety Agency (EFSA) has a different guideline than the Food and Agriculture Organization (FAO). There are also differences between countries’ recommendations. What to follow?

🗣️ Stay put as I unload the basket.

Credits: Canva.

🩺 Before I continue, however, this article is by no means medical advice. Please take it as inspiration. If necessary, consider consulting your primary doctor to deepen your quest.

🎯 For vegan veterans out there, supplementation of B12 is undoubtedly not a mystery, as most of you seem to be well-educated on the topic and pay increasing attention to meeting vitamin B12 intake recommendations. However, this is less the case for vegetarians.¹ I’ll refer to this finding below when describing the cross-sectional study conducted in Germany last year.

Why is vitamin B12 so important?

🧬 Vitamin B12 participates in DNA synthesis and is critical for the normal functioning of the nervous system and blood cell formation.

Its deficiency can lead to various disruptions in the body:²

• Postural hypotension (the sensation of losing ground or seeing black spots due to a blood pressure drop when you go from lying down to sitting up, for example)

• Gastrointestinal symptoms include alteration in bowel motility, such as mild diarrhea or constipation, and loss of bladder or bowel control

• Psychiatric and neurological disorders, including depression, memory impairment, confusion, psychosis, tiredness, muscle weakness, or loss of mental and physical drive

• Anemia

B12 provenance

🍽️ Although gastrointestinal microbes can produce B12 for their own metabolism needs (see section below), humans must ingest B12-rich foods to supply the body with this vitamin.

🔎 Plants do not synthesize it and, therefore, do not contain it. More recent research has identified seaweed and fermented foods as potential sources. Some will argue that the bioavailability of vitamin B12 may differ from each batch sold of those products, making them a less reliable source of intake when compared to animal-derived products.³ This area remains open for further investigation and analysis.

Primary sources of vitamin B12. *Values obtained from the work of Koseki K. and colleagues (link). Note the beauty of microorganisms' existence… We rely on them to keep our B12 levels in check.

The study

Quantitative studies assessing B12 status in adults provide valuable guidance for appropriate supplementation decisions. I came across the following research and thought it might be informative to you, too.

In a nutshell, the authors compared the nutritional status of healthy, free-living individuals who consumed either an omnivorous, vegetarian, or vegan diet for at least two years.⁴

Info adapted from (4).

👍 The excellent news:

Vegans: Healthy individuals on plant-based diets can secure an adequate vitamin B12 supply with over-the-counter oral supplements (250 µg B12/day taken over one year indicates an acceptable B12 status).

⛔️ Caution:

Vegetarians: This group had the most significant fraction of participants with suboptimal vitamin B12 status… Dairy and eggs might not be sufficient B12 sources. More studies are required to understand the limitations. Supplementation might be interesting for this group, too.

Omnivores: Although this group had the highest vitamin B12 intake from foods, many individuals failed to meet the current intake recommendations… The vitamin B12 content in modern foods of animal origin may be lower than previously thought. Evidence of lower B12 content in animal-derived foods aligns with the increased necessity for supplementing livestock with vitamin B12 and other micronutrients. Would it be due to the loss of microbial biodiversity in our soils?

If you are looking for supplementation

Keep in mind:

• Buy GMP-certified supplements. This manufacturing certification ensures that the substances are consistently produced and inspected according to high-quality standards. Not all supplements undergo strict control, so they are not made equal. Dr. Gunter, an OB/GYN doctor I follow on Substack, recently published an informative article on supplements. Have a peek for other detailed info (Gunter's Guide to Supplements).

• Consider B12 supplementation at mealtime if you follow a vegan or vegetarian diet.

• According to the European Food Safety Agency (EFSA), the adequate adult B12 intake is 4 μg/day,⁵ which is largely below the average of 250 µg B12 supplementation/day mentioned in the cited article. Dr. Greger suggests supplementation of 50 μg/day for healthy individuals on vegan, vegetarian, or flexitarian diets. Where to draw the line? It is a tricky question to which I have no clear answer. My approach is to seek medical guidance and follow my blood markers for some time to be sure my supply is adequate. I believe the same strategy can be helpful for those experiencing any of the above symptoms or who have recently switched to a vegan or vegetarian diet. Thoughts? What is your plan? Leave a comment.

To wrap up this topic, let’s get a final opinion from experts.

Position of the Academy of Nutrition and Dietetics: Vegetarian Diets (USA, 2016)

"It is the position of the Academy of Nutrition and Dietetics that appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases." 

"These diets are appropriate for all life cycle stages, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes." 

"Plant-based diets are more environmentally sustainable than diets rich in animal products because they use fewer natural resources and are associated with much less environmental damage." 

"Vegetarians and vegans are at reduced risk of certain health conditions, including ischemic heart disease, type 2 diabetes, hypertension, certain types of cancer, and obesity. Low intake of saturated fat and high intakes of vegetables, fruits, whole grains, legumes, soy products, nuts, and seeds (all rich in fiber and phytochemicals) are characteristics of vegetarian and vegan diets that produce lower total and low-density lipoprotein cholesterol levels and better serum glucose control. These factors contribute to the reduction of chronic diseases." 

"Vegans need reliable sources of vitamin B-12, such as fortified foods or supplements."

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Gut microbiome curiosity

🧫 In a healthy adult human gut, microbial communities have the ability to produce B12 at levels sufficient to meet their own metabolic needs. Whether humans benefit from this in-situ B12 microbial production is still unknown, and further research is necessary.⁶ I won’t be surprised if this is the case, though.

🤸‍♀️Until next week, stay B12 vigorous!

Xoxo,

Fernanda

PS1: Other articles you might find interesting:

• What Food Is Shaping You?

• Food As Medicine: An Old Concept Undergoing a Renaissance

• The Scent-sational Power of Body Odor

• Reversing Aging: The Plant-based Diet Approach

PS2: Find my archive here! Do you know that clicking in the heart or leaving a comment helps others discover this newsletter? Thank you for supporting my work.

1. Alexy U. et al., Nutrient Intake and Status of German Children and Adolescents Consuming Vegetarian, Vegan or Omnivore Diets: Results of the VeChi Youth Study. Nutrients. 2021 (link)

2. Brian C. Cobalamin Deficiency: Clinical Picture and Radiological Findings. Nutrients. 2013 (link)

3. Niklewicz A. et al., The importance of vitamin B12 for individuals choosing plant‐based diets. European Journal of Nutrition. 2023 (link)

4. Storz M. A. et al., A cross-sectional study of nutritional status in healthy, young, physically-active German omnivores, vegetarians and vegans reveals adequate vitamin B12 status in supplemented vegans. Annals of Medicine. 2023 (link)

5. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). Scientific opinion on dietary reference values for cobalamin (vitamin B12). EFSA. 2015 (link)

6. Kundra P. et al., Healthy adult gut microbiota sustains its own vitamin B12 requirement in an in vitro batch fermentation model. Frontiers in Nutrition. 2022 (link)