A dietary supplement is a concentrated source of nutrients or other substances with a nutritional or physiological effect. It aims to supplement your normal diet and do not eat as plain food. Kosttilskuddet er hverken et lægemiddel  or herbal medicine.

In practice, one can say that supplements legislative considered "food", while herbal perceived as "medicine". The number of supplements on the Danish market is unknown, but estimated to be over 1,000 different supplements.

Mange kosttilskud indeholder proteinpulver , vitamins and minerals. Other supplements contain herbal or fatty acids.Preparations with vitamins and minerals in normal dosage is always supplements. (High doses of vitamins and minerals as medicinal products and should therefore be registered as a strong vitamin and mineral product under the Medicines Act). In other cases, determines the manufacturer often even if the product to be marketed as dietary kosttilskud or herbal. This applies, for example ginseng, cranberry, garlic, echinacea and fish oil. Therefore, the market may be a little confusing because the same substance sold as different types of preparations. This means, among other things, that consumers get different information.