Selenium (Se) and iodine (I) are essential elements for humans, and their deficiency is widespread throughout the world. In order to obtain a functional nutritional product with an increased content of these trace elements in the vegetative experiment, foliar biofortification of two chervil varieties with selenium (sodium selenate 10 mg/l) and iodine (potassium iodide 100 mg/l) was carried out without and against the background of the use of silicon-containing fertilizers Siliplant (3 ml/l). The combined and separate application of selenate, iodide and Siliplant increased plants’ biomass. Siliplant utilization increased the accumulation of iodine by 1.7-1.9 times, and selenium supply – by 2.2-3.1 times. A significant increase in ascorbic acid content was provided by the combined supplementation of iodine and selenium (1.25-1.27 times), iodine and silicon (1.46-1.87 times) and joint application of selenium, iodine, and silicon (1.31-1.73 times), while an increase in total antioxidant activity (1.3-1.4 times) was observed for (Se+I) and (Se+I+Si) treatments. High varietal differences in the responsiveness of plants to the selected treatments were manifested, particularly an increase of polyphenols accumulation under separate and joint treatments of chervil with iodine and selenium by 1.26 times in the cultivar 21-20, and the absence of a significant effect in the cultivar 24-20. Taking into account the adequate consumption levels (ACL) of iodine and selenium, 50 g of the resulting functional product can provide up to 79% of iodine ACL and up to 40% in selenium ACL.