Choosing food supplements wisely: dosage, form, quality

Even if they look like medicines, food supplements are legally classed as foods. They do not need to be approved before sale; in Germany they merely have to be notified to the Federal Office of Consumer Protection and Food Safety (BVL). The manufacturer is responsible for safety and correct labelling, and food control authorities carry out spot checks.

This means there is no efficacy testing as there is for medicines. Food supplements may not claim to cure, relieve or prevent diseases – such claims are prohibited. There are as yet no binding EU-wide maximum levels for vitamins and minerals; in Germany, authorities are guided by the recommendations of the BfR.

If you eat a varied diet with plenty of vegetables, fruit, wholegrains, pulses and nuts, you are adequately supplied with most nutrients. The DGE therefore considers food supplements useful for healthy people only in certain situations.

Every pack states the recommended daily intake and the amount of each nutrient per daily dose. Often the share of the nutrient reference value (NRV) is also given as a percentage. The NRV is a guide value for labelling, not an individual recommendation. A value of several hundred or thousand per cent is not a sign of quality but an indication of a very high dose.

The BfR has recommended maximum levels per daily dose for food supplements. They take into account that you also get nutrients from your diet and possibly from fortified foods. Some examples:

Many products advertise themselves as “high-dose”, “extra strong” or a “year's supply”. That says nothing about quality, only about quantity. With water-soluble vitamins, most of any excess is excreted, but with fat-soluble vitamins such as A and D and with minerals such as iron, zinc or selenium, a long-term excessive intake can be harmful. Vitamin B6 is also problematic in large amounts.

So make sure the dosage matches your actual needs. Divisible tablets or drops allow a lower dose if a product contains more than necessary.

Tablets are cheap, stable and keep for a long time, but contain excipients for pressing. Capsules often manage with fewer additives; hard capsules made of cellulose are vegan, gelatine capsules are not. Powder can be dosed flexibly and is suitable for larger amounts, such as magnesium. Drops are practical for fat-soluble vitamins such as D and K. Gummies taste good but often contain sugar and smaller amounts of nutrients – and look like sweets to children.

With minerals, the compound plays a role: organic compounds such as citrates or bisglycinates are considered readily bioavailable. Terms such as “liposomal” or “bioactive” sound like added value; whether they bring a measurable advantage for healthy people is often unproven. Fat-soluble vitamins are best taken with a meal containing some fat.

The labelling of a food supplement sold in Germany must include, among other things, the designation “Nahrungsergänzungsmittel” (food supplement), the names of the nutrients it contains, the recommended daily intake, a warning not to exceed it, a statement that the product is no substitute for a balanced diet, and a note to keep it out of the reach of children. If this information is missing, be cautious.

Terms such as “lab-tested” or “premium” are not protected. Published certificates of analysis from independent laboratories, linked to a specific batch, are more meaningful. Products sold via online marketplaces directly from countries outside the EU are particularly critical: they do not necessarily comply with European food law and may contain prohibited substances or incorrect amounts. The German consumer advice centres (Verbraucherzentralen) report on conspicuous products on their portal “Klartext Nahrungsergänzung”.

In the EU, health claims may only be used if they have been scientifically assessed and authorised. Typical authorised wordings include “Vitamin C contributes to the normal function of the immune system” or “Magnesium contributes to the reduction of tiredness and fatigue”. Such claims describe a normal body function – not a promise that a product will noticeably improve anything in healthy, well-supplied people.

For many popular ingredients such as collagen, hyaluronic acid, ashwagandha or turmeric there are no authorised health claims. Statements such as “boosts your defences”, “detoxifies” or “for joint pain” are not permitted for food supplements. Those who advertise like this are often lax about the rules elsewhere, too. A reputable supplier uses cautious wording and names the nutrients a claim refers to.

Food supplements can interact with medicines and with each other. You should know a few well-known examples – if in doubt, your pharmacy can help.

The pack price says little. Compare the price per daily dose and consider how many days a pack actually lasts. Large “year's supply” packs are often cheap per day, but are only worthwhile if you really want to take the product for that long and the best-before date allows it. Store supplements in a dry, cool place away from light so that the ingredients remain stable.

On wovitamine.de you can see the price history of offers. This lets you tell whether a supposed special offer is actually good value compared with earlier prices.

Keep all supplements out of children's reach. This applies especially to gummies, which look like sweets, and to iron tablets, which can cause poisoning in children even in comparatively small amounts. Keep products in their original packaging so that dosage and warnings can be read at any time.

Food supplements are no substitute for a balanced, varied diet or a healthy lifestyle. If you have a pre-existing condition, are pregnant or breastfeeding, or take medication regularly, ask a doctor or pharmacist for advice before taking them. Do not exceed the recommended daily intake stated on the pack. The information on this page is for general guidance only and is no substitute for individual advice.