Read out They are available as pills, powders, effervescent and lozenges. They are colorful and upbeat and promise long-lasting vitality, beauty and health. We are talking about vitamin supplements. Famous is the story of the Nobel laureate in chemistry Linus Pauling, who swallowed vitamin C in the same way, even though it was known at the time that the body needed only a fraction of it. But of all things Pauling stayed fit until his old age. Since then, it has stood as proof that you can never get enough of vitamins. But with this stereotype, researchers now clean up thoroughly. "An overdose does not make sense for the healthy, " says Klaus Pietrzik, President of the German Society for Vitamin Research. Several vitamins can even cause harm when taken in high doses. Too much vitamin C causes kidney stones and diarrhea, too much vitamin A hair loss and too much vitamin D damages the bones, to name but a few.

Sadly, recently, beta-carotene was also given to smokers in twenty times the daily dose. In these high concentrations, it promotes - to the astonishment of the scientists and the suffering of the subjects - lung cancer. Nearly 400 of the 18, 000 smokers fell ill with lung cancer during the study. "In high doses, the effect of the vitamins changes, they then develop side effects like any other drug, " warns Pietrzik.

Nevertheless, he and other nutritionists recommend vitamin supplements to certain people. "If everyone were eating healthily - with five servings of fruit and vegetables a day, this would not be necessary. But many studies show that on average we are eating unhealthily, "complains Pietrzik. Unterversorgungen show, for example, in old people. Pietrzik's team found a deficiency in more than one third of the residents of a retirement home, especially with vitamin B12. In general, older people can no longer absorb the vitamin from the diet so well. "You should therefore additionally take part of the daily requirement for vitamin B12 in artificial form, " concludes the researcher. The vitamin is also recommended to vegetarians, as it occurs almost exclusively in animal products.

With vitamin folic acid, there is even a national shortage of the population. Thus, only one in four women reaches their daily target of 400 micrograms per day. This amount is necessary to prevent a serious disability of the baby, the neural tube defect. "Women should therefore take folic acid before and during pregnancy, " explains Hans-Georg Joost, Director of the German Institute for Nutrition Research in Potsdam. Pietrzik goes even further: "Since folic acid also protects against cardiovascular diseases and the national average values ​​are below the required daily amount, all people can equally supplement their diet with folic acid." Display

On the other hand, both scientists consider the indiscriminate grip on the shelf of vitamin tablets to be of little use. "Instead of paying attention to the right vitamin, many people buy supplements regardless of the content, but according to quantity, " criticizes Pietrzik. For example, a lack of vitamin H and vitamin B5 would not occur in this country. It is therefore groundless and nonsensical to take it artificially.

The situation is different with vitamin D. In the food it is found mainly in animal fats and is also formed in the skin using the sunlight. In small children, this own production is not enough. Especially not when they barely play outdoors: "There used to be cod liver oil for these backyard children. Today, we recommend vitamin D to all children. This protects against rickets, "says Joost.

Who can or should take which vitamin is different from case to case, whether pregnant or toddler. In the jungle of pills, there is rarely uniform advice for the layman. "The consumer is particularly confused when the competence, as so often, lies with the incompetents", Pietrzik denounces. For simplicity, therefore, he is in favor of a forced administration of certain vitamins such as folic acid. In the US, this has been happening since 1998 with folic acid-containing flour. Since then, the serious disability of the open back in newborns has decreased by 20 percent.

Susanne Donner

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