Effect of different doses of ultraviolet radiation on vitamin provision to the human body

Exposure of healthy adults to prophylactic doses of UV-radiation in the medium- and long wavelength spectrum improved metabolism of vitamins A, E and D and increased their content in the body. UV-irradiation even in prophylactic doses increased ascorbic acid requirements. Excessive UV-irradiation produced an adverse effect on the vitamin content. However, the vitamin concentration in blood was not significantly decreased. This can be explained by the adaptation of the human body to UV-irradiation upon a continuous increase of its dosage.