Foods fortified with vitamins, minerals and other additives as well as dietary supplements are very popular among health-conscious consumers. In the first part, methods of enriching food products not only with vitamins and minerals, but also with nutraceuticals such as polyphenols and polyunsaturated fatty acids are considered. The issues of vitamin stability are analyzed. The second part contains chapters on the analysis of vitamins and nutrients, fatty acid composition, as well as a chapter on assessing the bioavailability of nutrients. The book is intended for all specialists related to food enrichment and the development of dietary supplements, nutritionists, and will also be useful to scientists, teachers and students of specialized universities.