Vitamin D overdose


Every child knows that vitamins should be an important part of their diet and that they are good for the body. The same must then also for that Vitamin D be valid..? Or is it possible to have too much of what is actually necessary?
The daily dose recommended by doctors and nutritionists is included for everyone 20ug (20 millionths of a gram). The guideline values ​​for baby in the first year of life are up according to the young age 10ug limited daily. Normally every healthy body produces something 80-90% of the required vitamin D in the skin itself when exposed to sunlight. Only a small part of the daily requirement is absorbed through food. Above all, fatty fish species and cod liver oil play a leading role, some other foods play a subordinate role.

Read our general article on this Vitamin D

Because many people are now less exposed to the sun due to changed lifestyles, some speak of social Vitamin D deficiency and special dietary supplements (e.g. Vigantolettes) booming; Many health-conscious people take these willingly, many doctors are happy to prescribe them. In most cases this can be seen positively, but not in all:
Here too, as is so often the case, the dose makes the poison. Even vital things like vitamin D can cause negative side effects. You can even poison yourself with certain vitamins, namely the fat-soluble ones. But how do you recognize a vitamin D overdose and what should you do then?


Vitamin D belongs together with the vitamins E., K and A. (note: E-De-K-A) to the fat soluble Vitamins. Unlike the others, which are water-soluble, these need a fatty carrier to be able to be absorbed. In the body they are then at certain Transport molecules bound to float freely in the blood. But they can also be deposited in adipose tissue and accumulate there, so that the amount in the body increases continuously.
Water-soluble vitamins are released into the urine via the kidneys if they are present in greater numbers than they are needed and excreted in this way (dissolved in water). In the case of fat-soluble vitamins, this is only possible after going through some breakdown steps, which are much more specific.
There is a separate one for the breakdown of vitamin D. Enzyme group responsible, which converts the excess vitamin D so that it is with the Bile can be released into the stool. As a rule, however, this breakdown is not necessary, as most of the vitamin D required is produced by the body. This production is regulated and reinforced or inhibited as required. Unpleasant symptoms in connection with vitamin D occur in almost all cases only when food supplements are used improperly, for example when they are taken excessively.


A vitamin D overdose often manifests itself in nausea, weight loss and loss of appetite.

The symptoms of a vitamin D overdose include many rather unspecific things, which in their entirety can give the decisive clue. These include, for example, loss of appetite and weight loss, vomiting, constipation, abdominal cramps, high blood pressure, psychoses, but also muscle and tendon pain and headaches.
Cardiac arrhythmias can also occur in some people affected. Since the vitamin D increases the absorption of calcium in the intestine and additionally extracts calcium from the bones, too much calcium inevitably appears in the blood. One speaks of hypercalcaemia. As a result, it is only a matter of time before a large amount of calcium appears in the urine, as the organism is now trying to excrete the excess calcium. Those affected usually also show one Hypercalciuria (increased urine calcium levels).
Both of these lead to serious problems over a longer period of time: There are noticeable kidney damage, which is accompanied by an increased feeling of thirst and large amounts of water (Polydipsia) and frequent urination (Polyuria) accompanied. In addition, calcium deposits are found in almost all joints, soft tissues and muscles, which causes the pain mentioned above.
Long-term vitamin D overdose also threatens osteoporosis of the bones. Vitamin D overdoses in children usually show symptoms similar to those in adults. In addition, however, there are often growth disorders and a permanent increase in body temperature. A permanent and / or very strong vitamin D overdose can lead to death.

Both the overdose and the lack of vitamin D can lead to diarrhea. Intervention by the doctor may be necessary under certain circumstances. Read more about diarrhea from vitamin D at: Vitamin D diarrhea-is it dangerous?

Hair loss from a vitamin D overdose

Hair loss itself is always observed first of all as a symptom of the body that signals that something is wrong. The cause of these symptoms can be found in many different diseases. Not every type of hair loss can be explained in connection with vitamin D and even an overdose of it. On the contrary, hair loss - if it is in the context of vitamin D - is more of a sign of one Vitamin D deficiency! Too little vitamin D not only leads to a decrease in bone density with an increased risk of breakage (osteoporosis), but also to a shortening or shifting of the growth phases of the hair. The result is faster hair loss, which can even result in bald spots.

Side effects from vitamin D.

Vitamin D as an important and elementary food component and endogenous product is important for many functions of the human organism such as the Bone building. A natural intake via food and the body's own production usually have no side effects. If a sufficient amount is already available, the body automatically reduces its own production so that there can be no overdose. Unpleasant side effects (like those under Symptoms are described, see above) are almost exclusively through Nutritional supplements in doses that are much higher than those found in naturally occurring foods.


If there is a reasonable suspicion of a vitamin D overdose or even a reliable diagnosis, one should take action. Those affected should first consult their family doctor to determine the content of vitamin D and its precursors measure in blood allow. One speaks of a Mirror determination. If this confirms the suspicion of an oversupply with vitamin D, one should reduce the dose of the previously taken preparation or even discontinue it entirely.
As a rule, vitamin D levels in healthy adults are one for normal balanced nutrition with, for example, tuna or cod liver oil and regular exercise in the fresh air (and thus on the sunlight) perfectly adequate.
An exception to this are small children under one year of age and old people. The latter in particular naturally produce only small amounts of vitamin D and, due to other diseases, are often no longer outdoors enough. In these cases, vitamin D prophylaxis should nonetheless be discussed with a doctor. As part of the examination, he will also determine an individual daily dose and recommend an appropriate preparation. These control measures counteract unpleasant side effects of the therapy.

Vitamin D overdose in pregnancy

Due to the inconsistent study situation on vitamin D intake during pregnancy, such preparations should be avoided. In any case, you should consult your gynecologist for clarification.

Unfortunately, the current study situation is too inconsistent to be able to give recommendations for pregnant women regarding vitamin D food supplements or the risk of an overdose: While some studies describe vitamin D intake in the form of dietary supplements as protective for mother and child, other studies show that high vitamin D levels in the mother may later Allergy risk of the child increase.
Due to the uncertain data situation, gynecologists usually recommend that pregnant women take additional supplements to be on the safe side to renounce or to have regular blood count and vitamin level checks carried out in consultation with the supervising doctor. In principle, the uniform recommendation for pregnant women is one healthy diet and regular exercise outdoorsto get enough sunlight. Under these conditions there is no Vitamin D deficiency to be expected and supplements not necessary.

Please also read our article on this Vitamins in Pregnancy

Vitamin D overdose in the baby

Vitamin D deficiency prophylaxis is important in almost all cases, especially for small children and infants who naturally eat little food and thus little vitamin D, as a pronounced deficiency increases the risk of rickets, a bone disease also known as the English disease is called threatens. With their breast milk alone, the infants do not take in enough vitamin D, so that the recommendation of for all babies a vitamin D tablet (10 to 12.5 ug) Every day applies. This prophylaxis should be carried out in all children from around 8 days of age to the age of one. As a rule, no problems or side effects are to be expected with this therapy, which is common today.
Nevertheless, some babies are still noticeable during the vitamin D administration in the first year of life. These infants suffer from a special genetic defect that enables the correct formation of the Degradation enzyme of vitamin D prevents. So the children cannot produce vitamin D-degrading enzymes and thus cannot break down vitamin D. Because of this, excessive vitamin D administration leads to it Signs of intoxication such as severe hypercalcaemia (too much calcium in the blood), growth retardation, hormonal disorders, vomiting, dehydration, fever and also kidney damage in the form of calcification of the kidneys. One speaks of the clinical picture of idiopathic infantile hypercalcemia. It is estimated that 1 in 47,000 children is affected.