Many people turn to dietary supplements in the hope of alleviating symptoms, preventing deficiency symptoms or increasing their general fitness. When does this even make sense, what dosages are okay and when can it even become dangerous?
Whether in supermarkets, online, drugstores or pharmacies - the range of dietary supplements is huge and continues to grow. According to the Federal Statistical Office, around 180,200 tons were produced in Germany in 2020, almost 11 percent more than in the previous year. The value of the preparations manufactured rose by more than 23 percent from 900 million to 1.1 billion euros in the same period. The information service IQVIA has determined that last year alone German pharmacies made sales of 1.3 billion euros with food supplements, 4 percent more than in 2020.
According to a representative survey for the consumer monitor of the Federal Office for Risk Assessment (BfR), almost half of the population in Germany over the age of 16 takes vitamins from over-the-counter preparations. More than a third do this weekly, 16 percent even daily.
According to a Forsa survey commissioned by the consumer advice center, more than half of consumers believe that dietary supplements are beneficial to health. 35 percent consider the health benefits of vitamin supplements to be (very) high, 33 percent rate it as medium.
In fact, most dietary supplements are superfluous. The Institute for Quality and Efficiency in Health Care (IQWiG) writes, "whoever eats a balanced and varied diet gets all the nutrients that the body needs. It is therefore unnecessary to take additional vitamins and minerals."
IQWiG also points out that scientific studies have shown that food supplements are ineffective for some diseases. For example, vitamin C cannot prevent colds, "vitamin preparations also do not protect against cancer or cardiovascular diseases." According to the institute, it only makes sense to use food supplements when it comes to specifically correcting deficiencies.
Stiftung Warentest cites folic acid as one of the few examples that women who want to become pregnant or are in the early stages of pregnancy should take. Babies, those who are bedridden and the elderly may also need additional vitamin D. Vegans - including vegetarians in some cases - should consume B12, which is only found in sufficient amounts in foods of animal origin such as meat and dairy products. Women with heavy periods may need iron supplements.
If you have to or want to take dietary supplements, you should be well informed about the preparations. But that's not always easy. Because although almost half of the population believes it according to a Forsa survey, dietary supplements are not tested by the state for effectiveness and safety. Neither in Germany nor in the EU are there legal limits for the content of vitamins and minerals.
Dietary supplements are not classified as medicines, but as foods. On the one hand, this means that suppliers are not allowed to claim that their products have a pharmacological effect. On the other hand, manufacturers, dealers or importers are solely responsible for compliance with food law regulations. In order to put the preparations on the market, it is sufficient to send the Federal Office of Consumer Protection and Food Safety (FSVO) a sample and name the product and manufacturer, dealer or importer.
The content of vitamins and minerals in dietary supplements varies greatly. Manufacturers only have to state the recommended daily portion and indicate that it must not be exceeded. They must also point out that food supplements cannot replace a balanced diet and that they should not be kept within the reach of children.
Although consumers otherwise have to expect to pay too much for too little, the preparations can also be overdosed. There are no regulations that prevent this, either in Germany or in the EU. The BfR can therefore only publish proposals for maximum levels of vitamins and minerals in food supplements and fortified foods. The authority regularly adjusts them on the basis of scientific knowledge, which also takes into account the intake of vitamins and foods through the usual diet.
Not all manufacturers follow the recommendations. In 2020, for example, the consumer advice centers found that 57 percent of the products examined were overdosed on magnesium preparations. At Stiftung Warentest five years ago, 27 out of 35 vitamin supplements exceeded the recommended maximum levels. But a lot helps a lot is a fallacy, says BfR President Andreas Hensel. The dose decides whether minerals and vitamins are beneficial or harmful to health.
The manufacturers are not obliged to prove that their products are harmless to health, writes IQWiG. For example, research has indicated that supplements containing vitamins A, E and beta-carotene could increase the risk of certain diseases if taken for a long time and in high doses.
The institute advises extreme caution when ordering online. If preparations came from abroad, where other rules applied, they could be so high in doses that they would be considered medicinal products in Germany, it warns. Since the import of medicines from non-EU countries is prohibited, you run the risk of customs collecting your order.
According to the institute, people could also react to the plant substances contained and interactions with medicines are possible. Anyone who has been prescribed medication and regularly takes food supplements should therefore inform their doctor about it.
In general, IQWiG recommends considering before buying why you want to take the drug and whether there are scientific studies that prove that the preparation can do what you hope it can do. You should also ask yourself whether there are any disadvantages if you do without it.
Under no circumstances should one be impressed by advertising slogans. According to IQWiG, because the manufacturers are not allowed to advertise with a pharmacological effect, they try to make general claims that are mostly not proven and say nothing about an actual health benefit of the drug. Such statements are, for example, "supports the immune system", "has a balancing effect on the hormone balance" or "supports healthy joint function".
Stiftung Warentest has published overviews of vitamins and minerals. The tables explain why a substance is important to the body and how to ensure it is supplied through a normal diet. But you also learn when deficiencies are possible and what symptoms you can recognize them from. Finally, Warentest names the required daily intake of minerals and vitamins and how much of it you should take at most through supplements.
You can find a lot of further information in the special "Plain text food supplements" from the consumer advice center. Among other things, the legal aspects of the topic are explained in more detail and people who may need additional vitamins or minerals learn why this might be the case, which products are recommended and what else to look out for. Finally, checklists from the consumer center help with the decision for or against dietary supplements and with the use of the preparations.