Food supplements are a source of nutrients and other substances with a nutritional or physiological effect, and are sold in a form of »doses« (tablet, capsule, fluids in measured doses). Vitamins, minerals, amino acids, fatty acids, fiber and various plant and herbal extracts can be found in food supplements. The amounts of ingested food supplements will also determine their positive, negative, or unexpected effects on our body. In the case of multiple food supplement use or the use of food supplements in combination with medicines, -different interactions between them,- can lead to increased health risks or even organ damage. Food supplements can not replace a rich and healthy diet. Healthy individuals who think that even with a rich diet they can not fulfil their nutritional needs, whether macro or micro nutrient needs, reach for food supplements. This can lead to a nutritional overdose or, in the worst case, can have toxic effects. In case of nutrient poor food consumption, dietary supplements can help to meet the needs for various nutrients. The food supplement industry is quite aggressive and the consumers mostly buy what is being promoted as effective and easy to use, mostly regardless of any scientifically proven positive effects. The goal of marketing is to sell, not to provide real positive effects to the consumers. Consequently, possible negative effects of food supplements are not mentioned in marketing and- therefore remain unknown to the consumers.