Vital fiber is an insoluble fiber fraction made primarily of cellulose and lignin. It is used as a natural dietary supplement to compensate for the daily requirement for dietary fiber, i.e. a commonly known dietary fiber. The sources of vital fiber are psyllium plantain (Plantago psyllium) and plantain (Plantago ovale). The fiber contained in the seeds of these plants is not subject to digestive processes. After it enters the intestine, it swells, which determines its beneficial effect on the passage of food. Due to the development of industry and the increasingly common access to cheap and highly processed food, the supply of dietary fiber is not sufficient. Increasing the amount of dietary fibers is recommended in particular to obese people, who are on a reduction diet, or struggling with atherosclerosis.