Vitamin B12 on a Plant-Based Diet: How to Avoid a Deficiency

Why is vitamin B12 important?

If you eat fully or mostly plant-based, you might be wondering: how do I make sure I get enough vitamin B12 on a plant-based diet?

• Vitamin B12 is essential for several key processes in your body, including:
• Energy production – helps convert food into usable energy
• Nervous system – supports healthy nerve cells and brain function
• Red blood cell production – prevents anemia by aiding red blood cell formation
• DNA synthesis – crucial for cell growth and repair

A vitamin B12 deficiency can cause fatigue, poor concentration, anemia, and even irreversible nerve damage.

Where is vitamin B12 found?

Vitamin B12 is produced by bacteria. We need very little of it, but in today’s hygienic world it is no longer naturally present in our food. Nowadays, it is only found in animal products—in part because animals themselves are given B12 supplements.

If you eat fully or mostly plant-based, supplementation is necessary.

Although some plant-based alternatives, such as soy milk and meat substitutes, are fortified with B12, this is not enough to reliably prevent deficiencies.

Vitamin B12 supplements

For those following a plant-based diet, supplements are the only reliable source of vitamin B12. There are two main forms:

• Methylcobalamin (active form)
  Recommended for people over 65, those with chronic kidney disease, smokers, or those taking acid blockers or metformin.
• Cyanocobalamin (inactive form)
  The best option for most people: more stable, well-researched, and effective for long-term use.

How much vitamin B12 do you need?

Vitamin B12 is safe—even high doses are excreted by the body. It’s better to take too much than too little.

Adults (on a plant-based diet):

• Methylcobalamin: 1000 mcg per day
• Cyanocobalamin: at least 50 mcg per day, and 1000 mcg per day from age 60

Children:

• Ages 1–3: 10 mcg
• Ages 4–8: 25 mcg
• Ages 9–13: 50 mcg

The general recommendation from health authorities is 2.8 mcg per day, but this is based on absorption from animal foods.

With supplements, absorption works differently: only about 1% of high doses is absorbed passively. That’s why international experts recommend daily doses of 50–1000 mcg for vegans and vegetarians. These amounts are safe and proven effective in randomized controlled trials.

Vitamin B12 and health: key takeaways

• Vitamin B12 is crucial for energy, brain function, nerves, and red blood cell production.
• On a plant-based diet, supplementation is essential.
• Choose the right form (methylcobalamin or cyanocobalamin) and follow the recommended dosages.
• Regularly monitor your B12 status, especially if you are older, pregnant, or have absorption issues.

Conclusion: vitamin B12 on a plant-based diet

With the right supplements, it’s simple to get enough vitamin B12 on a plant-based diet. This ensures you avoid deficiencies and enjoy all the benefits of plant-based eating.

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In our Plants for Health lifestyle program, we guide you step by step with recipes, meal plans, practical advice, and expert support. Learn more about Plants for Health here.