The function of dietary substances allowing to talk about animal origin food enrichment at the primary level of its production is reserved for feed additives themselves. As nutrients, microelements play an important role in the proper functioning of any living organism. The eggs enriched with n-3 fatty acids are characterized by higher nutritional and health-promoting value. For this reason, they can be successfully classified as functional foods. Meat is an important source of vitamins B, and is concurrently characterized by the lower share of fat-soluble vitamins (A, D, E, K). The fatty acid content in the milk of cows is determined chiefly by nutritional factors. Mineral concentration in milk is related to physical-chemical equilibria, which are important in processing, nutritive value, and shelf life of dairy products. Dietary supplementation of ruminants with water-soluble vitamins is rarely used in practice. The methods of milk biofortification with vitamin B12 are important, since it is better absorbed from milk than from synthetic supplements.