If you are thinking about becoming vegan or are vegan already, you have probably heard about vitamin B12.

People often research or care about B12 only when they end their consumption of or cut back on animal products, but in fact, 40 percent of people who eat meat are deficient in this vitamin, compared to 50–60 percent of vegetarians. This is a very small difference!

Contrary to popular belief, vitamin B12 is not of animal origin. Bacteria produce this vitamin in organic soil and in the intestines of herbivorous animals and humans.

We compiled some of the main questions we have received on this subject, and Bruna Nascimento, licensed nutritionist and vegetarian support specialist in Brazil, replied to all of them. But if your question is not here, don’t hesitate to use our chat feature. We’ll be happy to help!

What is B12 for?

Vitamin B12 plays several roles in our bodies and is mainly related to maintaining the structure of the nervous system and the maturation of blood cells. It is also fundamental in over 100 chemical reactions.

Who needs to supplement B12?

As mentioned, vitamin B12 deficiency is not a concern exclusive to vegans; many factors may contribute to its malabsorption, including the use of certain medications (antacids, antihypertensives, oral contraceptives, etc.) and low stomach acidity due to improper chewing, age, or other causes. In people over 50, acidity in the stomach is often reduced. People who consume few or no animal products should also supplement B12, since their dietary intake of this vitamin is very low.

How should I supplement B12?

Ideally, to find out the best form of supplementation, you should consult a doctor or nutritionist, who can perform dosage tests for B12 and other supplements if necessary. They can then evaluate the best way to administer the vitamin, orally or by injection, as well as the best dosage. One cannot overdose on vitamin B12, but oversupplementation can cause acne.

What are the symptoms of B12 deficiency?

Symptoms include fatigue, poor memory and concentration, tingling in the extremities, and depression.

If we need to supplement vitamin B12, does it mean that veganism is not suitable for humans?

No. Human beings evolved in conditions very different from those of the present time. B12, being produced by bacteria in organic soil (without contamination of herbicides and pesticides), was present on food and in water (which were not sanitized or treated as they are nowadays). Food and water were sources of this nutrient.

In addition, we should note that at various stages of life, such as gestation, childhood, or old age, supplementation may be required. This can be because of low intake of nutritious food or problems absorbing nutrients from food. We also need to remember that we already consume vitamin or mineral supplements in many processed foods, often added to address the high nutrient deficiency in the general population.

Other Frequently Asked Questions

Are mushrooms, yeast, and algae sources of vitamin B12?

No. These groups have an analogous form of vitamin B12 that our bodies cannot activate. Therefore, they are not good sources of the vitamin. In addition, this form of B12 “interferes” in the diagnosis of B12 deficiency, because it binds to the same receptor that is evaluated in the examination. A person may show a high B12 index on the exam but exhibit symptoms of deficiency. So consulting a professional with knowledge in the field is important.

If I consume supplemented food products and achieve the minimum daily intake of 2.4 mcg, do I need to supplement it in other ways?

Doctors and nutritionists increasingly argue that the daily intake of just 2.4 mcg is not enough to meet the body’s demands and maintain proper B12 levels for most people. Therefore, for those who present some risk of malabsorption of B12 or do not ingest large amounts of food containing the vitamin, supplementation is recommended.

Humans store the vitamin in the liver. If I’ve just become vegetarian, do I need to worry about it now?

Yes. Considering the several factors that can alter the absorption of this vitamin and the great possibility of deficiency even with a diet that includes animal products, we recommend routine examinations every six months to evaluate the need for supplementation.

My examination results are within laboratory reference ranges. Is this OK?

B12 laboratory reference ranges are typically more than 148 pg/mL. But in clinical practice, we see that many people have symptoms with levels below 350 pg/mL. Because of this, we recommended maintaining the dosage above 490 pg/mL.

While we aim to answer some questions about vitamin B12, this blog post in no way replaces the advice of a professional with knowledge in the field. Consulting a doctor or nutritionist is an efficient and safe way to assess your particular needs, according to your stage of life, health, and goals.

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