Human life quality and activity are greatly influenced by nutrition since unhealthy diet can entail chronic diseases. Therefore, the authors of the paper make an attempt to dwell on some kinds of food products that are consumed by people on a daily basis, namely oils. The paper deals with the functional food that performs the energy function, as well as improves human being health. The authors of the paper put emphasis on fatty products, particularly vegetable oils that are not paid enough attention in the scientific literature. The polyunsaturated fatty acid content, physical and chemical parameters of vegetable oils available on the Russian market were studied. Two samples of salad oils, their biochemical parameters, composition and fatty acid content were characterised using GOST standards. The experiments were performed using white male rats, which were fed with salad oil. These experiments allowed assessing in the rats' bodies the amount of sulfur, an increase of which can lead to the increase in relative vital mass coefficients (heart, kidneys, liver, spleen) and demonstrate a certain negative impact on the organism of the rats, consuming salad oil containing sulfur.