Vitamin C is often taken orally, i.e. as an oral preparation. It is one of the most popular dietary supplements and its use is widespread. If doses are too high, however, it can cause diarrhoea. This is particularly the case if excessive doses of the vitamin have been swallowed over a long period of time. How much vitamin C has to be taken before diarrhoea occurs also depends on the situation and the state of health of the person concerned.
Causes
Diarrhea can occur especially after taking very large amounts of the vitamin. After eating foods rich in vitamin C or taking tablets in the recommended amount, there is usually no need to worry. Only a part of the swallowed vitamin C can be absorbed through the intestinal wall.
This is especially the case when large quantities are taken at once. The unabsorbed portion of the swallowed vitamin remains in the intestine. Vitamin C can have an osmotic effect there.
It therefore draws water into the intestine. The larger amount of water in the intestine makes the stool more fluid until diarrhoea can finally occur. Other symptoms, such as stomach problems or nausea, can also occur. Vitamin C can be present as an acid and thus lead to a slight acidity of the stomach. The amount of vitamin C that can be taken without causing diarrhoea seems to depend on the health situation of the person concerned.
Diagnosis
The diagnosis of diarrhea caused by vitamin C is mainly based on the connection between the intake and the symptoms. If vitamin C is responsible for the diarrhoea, the diarrhoea should start after high doses have been taken. If no further vitamin C is taken, the symptoms should also subside.
The amount of vitamin C ingested is also an important indication, as diarrhoea usually only occurs after taking very high doses. The diagnosis can be made more difficult, since vitamin C is often taken to treat or prevent infectious diseases. If the person was already ill before taking vitamin C, it is often not clear whether the diarrhoea was caused by taking vitamin C or by the original illness. Diarrhea can occur for many reasons. A doctor should be consulted, especially if the diarrhoea lasts longer.
