“…In old age, it is possible both for the body to be deficient in some vitamins and minerals, and its oversaturation. During the physiological process of aging, the metabolism of a number of vitamins undergoes a change, which causes vitamin deficiency in elderly people, which is caused by poor nutrition or impaired absorption of vitamins (Poltarykhin, Voronkova, 2020;Poltarykhin, Ivanova, 2020;Yemelyanov et al, 2019a,b;Puryaev and Puryaev, 2020;Gladilina et al, 2018;Bekmansurov et al, 2019;Nefedov et al, 2019;Kuzmin et al, 2020).…”