Can You Take Too Much Vitamin B12?

Can You Take Too Much Vitamin B12?

We all need to consume enough vitamin B12 to support our health, but one question you may have is this: can taking too much vitamin B12 be dangerous?

If you’re interested in learning more about how much vitamin B12 is the right amount and when we should worry that we’re getting too much, keep reading. We have everything you need to know about the safety of this important nutrient.

Vitamin B12 is considered safe even at high doses, as it’s a water-soluble vitamin that gets excreted from the body quickly. There is no tolerable upper-level intake for vitamin B12, which means large amounts of this vitamin will not typically cause adverse effects.

To fully understand why vitamin B12 is one of the safest dietary supplements, it’s important we learn more about how this vitamin works and why our bodies need a regular intake to maintain optimal health.

What is vitamin B12?

Vitamin B12 is an essential water-soluble nutrient that our bodies need to support many important functions, such as:

  • Red blood cell production

  • DNA synthesis

  • Nerve cell function

  • Cognitive development

We need to maintain adequate amounts of vitamin B12 to avoid a B-12 deficiency and support the systems that play a vital role in our health.

But you may be wondering: is it possible to intake too much of this essential nutrient?

How vitamin B12 is stored in your body?

To fully understand how much of this vitamin we’d need to take to notice side effects, we first need to learn about our body’s ability to absorb this nutrient.

Vitamin B12 is a water-soluble vitamin, which means it’s best dissolved and absorbed in our bloodstream with water.

This also means that vitamin B12 is quickly excreted from the body via urine, and cannot be stored in our systems for long periods of time. For this reason, we need to be intaking this vitamin every day to maintain adequate levels of B12.

How much vitamin B12 is too much?

According to research, there is no tolerable upper intake level of vitamin B12. This means that health experts have not discovered an amount of this vitamin that could be taken to pose a threat to our health.

This is primarily because, as we’ve mentioned, any excess vitamin B12 in our bodies gets excreted out.

However, it’s important to note that there are circumstances in which adverse effects have been reported. 

For example, one study by Clinical Toxicology found that a woman taking high doses of vitamin B12 supplements (12 mg in total) to counteract a severe deficiency experienced symptoms of toxicity.

Side effects of vitamin B12 toxicity

While it’s incredibly unusual to experience side effects from vitamin B-12 supplements, as studies show this vitamin is safe even when administered at 300–3000 times the recommended amount, it’s important to stay fully informed.

Side effects of vitamin B12 toxicity may include:

  • Acne
  • Heart palpitations
  • Anxiety
  • Shortness of breath
  • Numbness and tingling
  • Joint pain
  • Fever
  • Itching or rash

If we’re noticing any of these symptoms, we should consult a doctor for medical advice and stop taking vitamin B12 supplements until told otherwise.

Recommended daily intake of vitamin B12

See the table below to determine how much vitamin B12 you should be taking per day to satisfy nutritional needs.






0-6 months

0.4 mcg

0.4 mcg

7-12 months

0.5 mcg

0.5 mcg

1-3 years

0.9 mcg

0.9 mcg

4-8 years

1.2 mcg

1.2 mcg

9-13 years

1.8 mcg

1.8 mcg

14-18 years

2.4 mcg

2.4 mcg

2.6 mcg

2.8 mcg

19+ years

2.4 mcg

2.4 mcg

2.6 mcg

2.8 mcg

Data from the National Institutes of Health

For more information and an explanation of which groups are most at risk for vitamin B12 deficiency, check out our article: How Much Vitamin B12 You Need Per Day

Final thoughts

Vitamin B12 is an important nutrient that our bodies need to function, which is why we should all be including this vitamin in our diet.

For anyone concerned that they may be taking too much, don’t worry - it’s extremely unlikely that vitamin B12 could stay in the body long enough to cause unwanted side effects or pose a health concern.

In fact, vitamin B12 deficiency is a far more widespread and serious problem than vitamin B12 toxicity.

That’s why FuelOrganics offers a high-quality vegan vitamin B12 supplement designed to support our overall health.

Trusted sources

  1. Allen L. H. (2012). Vitamin B-12. Advances in nutrition (Bethesda, Md.), 3(1), 54–55.
  2. Morales-Gutierrez J, Díaz-Cortés S, Montoya-Giraldo MA, Zuluaga AF. Toxicity induced by multiple high doses of vitamin B12 during pernicious anemia treatment: a case report. Clin Toxicol (Phila). 2020 Feb;58(2):129-131. doi: 10.1080/15563650.2019.1606432. Epub 2019 Apr 24. PMID: 31018715.
  3. Vitamin B12. Fact sheet for health professionals. National Institutes of Health. Office of Dietary Supplements. Retrieved from

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