– The dose makes the poison: This also applies to dietary supplements. These can – in certain quantities – be beneficial to health, but can also be dangerous in case of overdose.
Vitamins are among the “essential substances”. This means that although the body urgently needs these substances, it cannot produce them independently – with the exception of vitamin D – but must absorb them, for example, through the diet. Normally, a balanced diet is sufficient to provide the body with all the vitamins and minerals it needs. According to a report in “AOK Health Magazine”, supplements are only necessary if there is a vitamin deficiency, which the doctor can diagnose through blood tests.
However, the market for nutritional supplements is expanding: according to the “Techniker Krankenkasse”, people in Germany spend more than a billion euros on such preparations every year. In most cases it is not absolutely necessary to take it; In the worst cases, an overdose can pose significant health risks. Be especially careful with these vitamins:
There is a risk of gastrointestinal problems and an increased risk of bleeding if you take vitamin E long-term and without medical advice. According to the European Food Safety Authority, 300 milligrams is considered the maximum tolerable dose per day. But: The consumer advice center warns of a significantly lower value. The frequency of cerebral hemorrhage increases by only 130 to 200 milligrams per day.
A similar requirement applies to vitamin B12. This preparation should only be taken after consulting a doctor to avoid the risk of serious side effects. Opinions differ when it comes to maximum daily amounts: the Federal Institute for Risk Assessment suggests a limit of 25 micrograms via dietary supplements, while the German Nutrition Society (DGE) speaks of four micrograms per day. The risk: Vitamin B12 is an important growth factor – for all cells, including cancer cells. According to an NDR report, based on current studies, too high a level of vitamin B12 in the blood may be associated with an increased risk of lung cancer.
Acute nausea, loss of appetite, abdominal cramps and vomiting as well as, in severe cases, kidney damage, cardiac arrhythmias and loss of consciousness can result from a vitamin D overdose – and in the worst case, be fatal. This emerges from a report by the Robert Koch Institute. All these consequences are due to the increase in calcium levels, which occur in the human body due to excessive intake of vitamin D. “Since vitamin D can be stored in the body, an acute and gradual overdose is possible,” writes the Robert Koch Institute .
An overdose of vitamin B3 can also be fatal. If the critical maximum amount of 35 milligrams per day is exceeded, there is a risk of heartburn, headaches, diarrhea and abdominal pain, as well as potentially fatal drops in blood pressure and liver damage.
According to the consumer advice center, vitamin B6 influences hormones and nerves as well as metabolism in humans. According to the report, deficiency occurs very rarely, as the necessary requirements are normally met through a balanced diet. However, athletes in particular enjoy taking the vitamin – individually or in the form of combined nutritional supplements. An overdose damages the nervous system. Those affected suffer from unsteady gait and are therefore prone to falls. The Federal Institute for Risk Assessment (BfR) recommends a maximum amount of 3.5 milligrams per day for added vitamin B6 in the form of dietary supplements.
Pregnant women in particular need to be careful when taking doses of vitamin A. An overdose can reduce bone stability and, in pregnant women, harm the fetus. According to the consumer advice center, the maximum daily dose of vitamin A is 3,000 micrograms.
The heart is particularly at risk if there is an overdose of calcium: if you take too many corresponding dietary supplements, you run the risk of suffering a heart attack. Martin Smollich, professor of pharmaceutical nutrition, explains the dangers in an interview with the “Spektrum” knowledge portal: “The risk is demonstrably increased with a daily dose of more than 1,500 milligrams of calcium”.
An excess of potassium in the blood can be fatal and must therefore be treated. Possible consequences include intestinal obstruction, muscle weakness and paralysis, as well as lung failure and cardiac arrhythmias. This emerges from a DGE report. The maximum five to six grams you consume per day on a normal diet is harmless if your kidney function is intact.