What are dietary supplements?

According to German law, dietary supplements are regarded as food products, not drugs. Drugs are pharmacologically active substances that have a particular effect on the body and its functions. They are taken to relieve symptoms and illnesses, or for prevention. Dietary supplements do not have a pharmacological effect, and manufacturers aren't allowed to claim that they do – their sole purpose is to provide the body with nutrients. For this reason, they have different quality and safety requirements than chemical or herbal medicines do.

In Germany, the responsibility for the safety of dietary supplements lies with the manufacturers and retailers – as it does with all food products. All dietary supplements must be registered with the German Federal Office of Consumer Protection and Food Safety (BVL). For dietary supplements, the authorities only record which ingredients are listed on the label. But they, or the official food monitoring employees at the manufacturing site, can take samples of the products to check them.

So dietary supplements don’t have to go through all of the strict tests and quality assurance processes that are required of medicines before they are sold on the market. This means that it’s not always possible to be sure that all dietary supplement products have the same quality.

It is a good idea to be especially careful when ordering products on the internet. Products that are ordered from abroad will not automatically conform to German food safety laws. Because other countries have different regulations, a dietary supplement might contain such a large amount of a substance that it would be considered a drug in Germany. It could also contain substances whose use is considered hazardous to your health by German regulators.

Because dietary supplements are regulated like food products rather than like medicines, they are not allowed to be advertised as substances that cure, relieve or prevent illnesses, or that are suitable for a specific therapeutic use. That is why dietary supplements are often claimed to have more general effects such as “supports your immune system,” “has a hormone-balancing effect” or “supports the health of your joints.” It is important to know that most of these claims are unproven, though, and don't tell us anything about the actual health benefit of taking the product.

If you eat a balanced and varied diet, you will get all the nutrients your body needs. So you won't need to take extra vitamins or minerals. In certain cases, it may make sense to take dietary supplements on a temporary basis with the specific aim of correcting a deficiency.

But some dietary supplements have been proven to have no effect on certain illnesses. For example, studies have shown that – contrary to popular belief – taking vitamin C cannot prevent a cold. Vitamin supplements do not help to prevent cancer or cardiovascular (heart and blood vessel) disease either.

Because manufacturers of dietary supplements don’t have to provide evidence that their products are safe, harmful effects can’t always be ruled out. There are some dangerous or hazardous substances that dietary supplements aren’t allowed to contain. But vitamins and other substances can also be harmful to your health. Some people might have allergic reactions to plant-based ingredients, for example.

Research suggests that products containing vitamin A, vitamin E, or beta-carotene might increase the risk of developing certain diseases might increase the risk of developing certain diseases when taken over a longer period of time and at a high dose. For this reason, the German Federal Institute for Risk Assessment (BfR) requires all manufacturers of vitamin supplements to limit the amounts of e.g. carotenes in their products.

Also, dietary supplements may affect the way medicines work. For this reason, if a doctor prescribes medicine for you, it’s important to let them know if you are regularly taking any dietary supplements.

People who are considering taking dietary supplements should ask themselves the following questions first:

• Why do I want to take this product?
• Is there scientific research showing that this product will help me to reach that goal?
• Would there be any disadvantages if I did not take this product?
• What other ways are there to do something good for my health?

You can find more information at the German Federal Institute for Risk Assessment (BfR).