Ultraviolet irradiation to enrich foods with vitamin D

Vitamin D deficiency found in 50-90 % of the adult and children's population in Russia (I.N. Zakharova et al., 2015; V.M. Kodentsova et al., 2017, 2018) and caused by inadequate intake and reduced endogenous synthesis in the skin due to insufficient solar irradiation, is associated with many chronic diseases and makes an important problem (A. Hossein-nezhad et al., 2013). One of the options for biofortification, called “bio-addition”, is based on the ability of living organisms to form vitamin D from endogenous ergosterol by UV irradiation. Ultraviolet irradiation of animals allows minimizing seasonal variations in the concentration of vitamin D in cow's milk (R.R. Weir et al., 2017). A one-hour exposure of animals for 14-day to insolation at summer noon increased the vitamin D3 content in pork (p