Our body cells need vitamin B12 to function properly. Accordingly, the cobalamines, as the vitamin B12 compounds are also called, are essential for our health. But is there too much of a good thing? What exactly happens with a vitamin B12 overdose?
We get the valuable vitamin from different sources – but the only really effective ones are animal products. If you do not use them, it is almost impossible to intake B12 over food.
People with a vegan or vegetarian diet are therefore often advised to cover their vitamin B12 needs with dietary supplements. Since dosage of the vitamin here often fluctuates greatly, you may have already asked yourself the legitimate questions:
Is that enough?
Is that even too much?
What happens if I take too much vitamin B12?
Below in the article you will find the answers.
How does vitamin B12 overdose come about?
First of all, a warning can be given: an overdose of the vitamin is hardly possible in healthy people by oral intake. Generally speaking, if you take more vitamin B12 than your body needs, the excess is excreted again in a healthy organism without any problems.
Too high a dose therefore usually has no negative effects on the functions of the vitamin in the body, such as the activation of folic acid or DNA synthesis.
For this reason, EFSA (European Food Safety Authority) published an opinion in 2015 in which it argued for no previously known health risks when taking vitamin B12 supplements.
Since there is therefore no prescribed maximum dose of the vitamin, the fluctuation range for dietary supplements with vitamin B12 ranges from 100 to 3000 micrograms (micrograms) of the contained substance. Although experts even consider the high levels to be harmless, it should not be exaggerated when taking the vitamin preventively every day. If there is no shortage, the excess B12 simply does nothing.
It makes more sense to take higher-dose preparations every week.
Our body has a sophisticated tool for storing the substance: our liver. It is able to store up to 5000 micrograms of the vitamin. This depot can then be used up over a longer period of time.
Healthy individuals who also use animal products during their diet are usually 9 micrograms as a daily maximum feed.
If there is a deficiency due to the diet (vegan/vegetarian) or a disease, high-dose dietary supplements make sense.
The main causes of a B12 overdose are therefore certain diseases or direct administration of the substance into the bloodstream.
Diseases that can lead to an overdose of vitamin B12 usually affect the organ that stores B12 in our body: the liver.
- Liver tumors
- Autoimmune diseases
In addition, an allergic shock can occur with a high-dose vitamin B12 injection. However, this risk exists only when injected and is also rare.
As you can see, vitamin B12 overdose is not so easily possible. But what are its signs and what effect does it have on your body?
Side Effects with Vitamin B12 Overdose
Since an excessive dose of vitamin B12 in the blood is usually triggered by an organ disease, the overdose itself is a symptom of certain diseases. There are no signs that specifically indicate too much B12.
Nevertheless, vitamin B12 is often associated with the development of acne or skin eczema. Is there anything wrong with it?
Can too much vitamin B12 trigger acne?
Yes, in rare cases, an overdose of vitamin b12 can trigger acne, eczema or rashes on the skin – but this was only observed after parenteral intake of the substance.
What does that mean? Parenteral means taking a substance bypassing the gastrointestinal tract. The skin reactions were thus only caused by external use of vitamin B12 (e.g. by spraying).
This is therefore not the case with intake in the form of food or dietary supplements.
Too much vitamin B12 and cancer: What is the link?
Several studies see a statistical link between an increased cobalamin level and the development of cancer. What exactly does that mean? Can a vitamin cause cancer?
Here, too, a warning can be given. Vitamin B12 is, after all, a major factor in cell division. If this process gets out of control in our organism and our cells divide uncontrollably, cancer develops.
The studies thus conclude that there is indeed a link between vitamin B12 and cancer. However, it can be assumed that the increased B12 value is only the result and not the cause of the disease.
Although the link has not yet been sufficiently studied, an increased vitamin B12 value may be an indicator that these people are more at risk of developing cancer, especially in high-risk groups (e.g. the elderly, smokers).
Vitamin B12 in pregnancy: Do I need to pay attention to an overdose?
In general, two guiding principles apply here:
- You have an increased need for vitamins, minerals and trace elements during pregnancy.
- Dietary supplements can support your body and that of the adolescent child – but the intake should always be clarified with the doctor. Not all supplements are tolerated during pregnancy.
Vitamin B12 is extremely important for embryonic development. Especially vegan mothers often notice a craving for meat or other animal products during pregnancy.
The body tells you that it lacks certain nutrients. Actually quite practical.
Even more practical is that as a vegan or vegetarian, you don’t have to give up your desired lifestyle during pregnancy these days. Supplements help to meet the need for all essential substances and support healthy development of the baby. Your doctor can advise you on this.
Overdoses are usually also unproblematic in pregnant women, as the excess is excreted in healthy organs.
So how problematic is an overdose of vitamin B12?
By diet or dietary supplementation, overdoses of B12 are hardly achievable in healthy people for physiological reasons. The rare cases in which a negative reaction could actually be observed after the administration of high doses of vitamin B12 occurred as a result of external or intravenous use.
Furthermore, high B12 values are often the result of certain diseases rather than their cause.
However, it certainly does not harm to spare your own body: if you do not undergo any special therapy, which requires a high intake of vitamin B12 (e.g. after a diagnosed deficiency), you do not have to resort to high-dose supplements every day. It makes more sense to take the preparations weekly, as the vitamin can also be stored in your liver in high doses.
Especially if you are vegan or vegetarian, you are much more likely to be at risk of a vitamin B12 deficiency than an overdose. The intake of supportive preparations is also strongly recommended from a scientific point of view.
To find the optimal dose for you, you should listen to your body completely. After all, you often know best what is good for you. In addition, it is always worthwhile to visit the family doctor, who will be happy to advise you on this.