Vitamin D overdose: the most important questions and answers

Vitamin D Überdosis: Die wichtigsten Fragen und Antworten

Vitamin D is required by our body for various complex tasks and it is without a doubt one of the most important vitamins our body needs. Vitamin D is very important for the bones, the muscles, our circulation and our well-being, among other things.

But the correct dosage is crucial. A vitamin D overdose has different negative effects on our body and leads to unpleasant to dangerous symptoms.

With this article we want to explain to you how a vitamin D overdose can occur, how it manifests itself and how to treat it.

the essentials in brief

  • Vitamin D is one of the most important nutrients for the body and is required for several important processes. We need vitamin D all the time, but very small amounts are enough to meet our needs. We absorb vitamin D naturally from the sun and from food.
  • A vitamin D overdose is when the daily requirement is far exceeded. A distinction is made between an acute and a chronic vitamin D overdose. An overdose can only take place through dietary supplements.
  • A vitamin D overdose can cause unpleasant and sometimes dangerous symptoms and side effects and in some cases requires treatment.

Vitamin D overdose: What you should know

Our body needs vitamin D all the time, but very small amounts are enough to cover the daily vitamin D requirement. The topic of vitamin D overdose, on the other hand, is more complicated and raises various questions.

We would now like to introduce you to the most important questions about vitamin D overdose and answer them in the best possible way with the help of various studies and scientific approaches.

How much vitamin D does our body need and how do we absorb it?

In contrast to other vitamins and nutrients, vitamin D is generally very special because our body can produce and process most of it itself. The human body depends on being able to produce vitamin D independently. (1)

Because of the sun's rays, vitamin D is produced and fed through the skin and can then be used by our body.

sun shines plant

Especially in the summer months, the body absorbs a lot of vitamin D from the sun. (Image Source: Jordan Stewart / unsplash)

The vitamin D obtained is not necessarily processed directly or used by the body. Because vitamin D has the special property that it is deposited and stored in the fatty tissue of the body. This way, when the body needs vitamin D, it's readily available.

The need for vitamin D that we produce through the sun is in most cases 70 to 90%. The sun is, so to speak, our main supplier of vitamin D. We get the rest of it through food.

Most of the vitamin D requirement is produced by the body itself through exposure to sunlight.

Fatty fish, eggs or mushrooms contain traces of vitamin D. However, this proportion is very small and it is impossible to meet the vitamin D requirement from food alone. Vitamin D supplements, which are intended to cover the need in the form of tablets, capsules or drops, are therefore particularly popular.

How much vitamin D you need depends on various factors. Age plays the biggest role here, but general health and possible previous illnesses are still a factor.

Old Daily requirement in µg (micrograms)
0 - 12 months 10
1 - 14 years 15 - 20
15 - 65 years 20
from 65 years 15 - 20


Of course, these values ​​also vary from person to person. Furthermore, as an adult you should not consume more than 100 micrograms of vitamin D per day, for children this value is around 50 micrograms per day.

What is a vitamin D overdose?

A vitamin D overdose occurs when the recommended maximum requirement per day is briefly exceeded or exceeded over a longer period of time. As already mentioned, the maximum recommended requirement for adults is around 100 micrograms of vitamin D per day. (4)

One speaks of an acute vitamin D overdose when too much vitamin D has been taken in a short period of time, while in the case of a chronic vitamin D overdose this happens continuously over a longer period of time.

Chronic vitamin D overdose is far more dangerous than a one-off overdose. However, even a single, excessively high dose can lead to poisoning and this can also be dangerous under certain circumstances.

It is therefore extremely important not to exceed the specified maximum amount of vitamin D per day, otherwise a vitamin D overdose can occur and this is associated with unpleasant consequences and side effects.

How does a vitamin D overdose occur?

We have already explained to you how our body can absorb vitamin D and what needs to be considered. The main supplier of vitamin D is the sun, through whose radiation vitamin D is produced through the skin and enters our body naturally.

However, the sun's rays cannot lead to an overdose of vitamin D, since the amount produced is not large. Even a very long, intense sunbath can never lead to a vitamin D overdose. Therefore, there is no need to worry about getting a vitamin D overdose from the sun.

The situation is similar with food intake. We can get vitamin D from fatty fish, eggs or mushrooms, among other things. Again, it is virtually impossible to get too much vitamin D from food.

You would simply have to eat a ton of food to overdose, so there's no need to worry about consuming too much vitamin D through food.

The main reason for a vitamin D overdose is taking supplements, specifically vitamin D supplements. (5.9"> In principle, this is the only realistic way to consume too much vitamin D.

Capsule vitamin D

Vitamin D supplements are mainly taken in the event of a vitamin D deficiency, but they must be dosed correctly. (Image source: nicolas solerieu / unsplash)

In principle, it is not bad to take in vitamin D via food supplements, since many people can experience a temporary vitamin D deficiency, especially in the winter months. However, it is very important that these vitamin D supplements are taken sensibly and in consultation with a doctor takes. (6)

What is a vitamin D overdose?

A vitamin D overdose can manifest itself in a number of ways, but this varies from person to person and also depends on the severity of the overdose, the general condition and whether there are any interactions with other diseases.

A single overdose can even happen unnoticed and even be symptom-free. A single, slight overdose of vitamin D is therefore not a cause for concern.

The situation is different in the case of an acute or, even more so, a chronic overdose of vitamin D. There may be some unpleasant side effects or symptoms. (8.10)

We have listed these below:

  • nausea and diarrhea
  • sluggishness and severe fatigue
  • Dry mouth and throat
  • muscle and bone weakness
  • loss of appetite
  • Kidney stones to kidney failure

However, kidney stones and kidney failure in particular only occur in the event of a severe, chronic overdose spread over a long period of time. (7)

man is in pain

A long-term overdose of vitamin D manifests itself at many levels in the body. (Image source: Francisco Gonzalez / unsplash)

Excessive consumption of vitamin D also causes excess production of calcium and magnesium in the body. Some of these minerals are also released from the bones in the event of a chronic vitamin D overdose, which weakens them in the long term. (9)

However, the above symptoms do not have to be a clear indicator of a vitamin D overdose. In any case, it should be diagnosed. In addition, the symptoms and side effects are always different.

Is a vitamin D overdose dangerous?

Whether and how dangerous a vitamin D overdose is depends primarily on whether it is a one-time event or whether it occurs continuously over a longer period of time. In addition, it also depends on the severity of the overdose and the general condition of the person concerned. (7)

A single, mild to moderate overdose of vitamin D is not particularly problematic, and this rather milder form of overdose does not even necessarily have to result in symptoms or side effects.

An acute, severe overdose, on the other hand, is critical, since the symptoms can occur in an increased form here. In the event of vitamin D poisoning, an emergency doctor or medical help should always be sought.

A chronic overdose is also dangerous because the symptoms can be more severe and different than a single overdose.

The weakening of the body and the kidneys is particularly dangerous with a long-term vitamin D overdose.

This can lead to everything from kidney stones to kidney failure. In addition, it is often noticeable that with a chronic vitamin D overdose, the muscles and bones are weak and hardly resilient due to the loss of minerals. (9)

Basically, you can't really answer this question in a meaningful way, because as a layman you can't make any precise statements about how long or how severe the overdose has been. However, there is a risk of an overdose of vitamin D.

How is a vitamin D overdose treated?

A vitamin D overdose brings with it some side effects and symptoms, some of which are more severe. When it comes to treatment, the main question is which symptoms occur and how severe they are.

In principle, of course, the supply of vitamin D, especially through supplements, is stopped immediately. Due to the storage in the fatty tissue of the body, those affected with a diagnosed vitamin D overdose still have more than enough excess vitamin D in the body.

Then, depending on the severity of the overdose, the mineral balance is normalized again. Because of the overdose of vitamin D, those affected produce a lot of calcium and even pull it out of their bones and muscles.

This usually results in a low-calcium diet so that the mineral balance in the body can be regulated again. In addition, overdoses of vitamin D often lead to a loss of water in the muscles and bones and those affected are partially dehydrated. Therefore, during the treatment, care is taken to ensure that the body absorbs enough water again. (9)

In the case of a severe course or vitamin D poisoning, the person concerned usually has to be hospitalized and treated there, since the circulatory system in particular can be very unstable here.


Vitamin D is very important for our body and takes over some essential tasks there. It is supplied naturally through sunlight and food. Vitamin D as a dietary supplement only makes sense if a doctor has diagnosed a vitamin D deficiency.

A vitamin D excess is only triggered by dietary supplements and vitamin D preparations and, depending on the type and severity, can be quite dangerous. Severe courses must be treated and monitored, as they sometimes have severe side effects and symptoms.


  1. Vitamin D. BY SOPHIE KELM, UPDATED ON 07/24/2018 - Apotheken Umschau
  2. New Reference Values ​​for Vitamin D German Nutrition Society, Bonn, Germany Ann Nutr Metab 2012;60:241-246 DOI: 10.1159/000337547 - Published online: June 1, 2012
  3. Answers from the Robert Koch Institute to frequently asked questions about vitamin D Robert Koch Institute, as of January 25, 2019
  4. Scientific Opinion on the Tolerable Upper Intake Level of vitamin D DOI: 10.2903/j.efsa.2012.2813 EFSA Journal 2012;10(7):2813
  5. Vitamin D products - when are they useful? Consumer center NRW - status: 25.11.2020
  6. New reference values ​​for vitamin D German Society for Nutrition e. V. - Public relations department: Antje Gahl Status: 01/10/2012
  7. Vitamin D Fact Sheet for Health Professionals National Institutes of Health, Bethesda, MD 20892-7517 - October 9, 2020
  8. Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P, Jones G. Vitamin D Toxicity-A Clinical Perspective. Front Endocrinol (Lausanne). 2018 Sep 20;9:550. doi: 10.3389/fendo.2018.00550. PMID: 30294301; PMCID: PMC6158375.
  9. Burt LA, Billington EO, Rose MS, Raymond DA, Hanley DA, Boyd SK. Effect of High-Dose Vitamin D Supplementation on Volumetric Bone Density and Bone Strength: A Randomized Clinical Trial. JAMA. 2019 Aug 27;322(8):736-745. doi: 10.1001/jama.2019.11889. Erratum in: JAMA. 2019 Nov 19;322(19):1925. PMID: 31454046; PMCID: PMC6714464.
  10. Galior K, Grebe S, Singh R. Development of Vitamin D Toxicity from Overcorrection of Vitamin D Deficiency: A Review of Case Reports. nutrients. 2018 Jul 24;10(8):953. doi: 10.3390/nu10080953. PMID: 30042334; PMCID: PMC6115827.
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