The skin uses ultraviolet radiation (UV) to synthesize the vitamin D3.
Excessive exposure to UV radiation is harmful, producing sunburn, aging
and cancer.
UVB radiation (ultraviolet B) is responsible for 80-90% of these effects
and UVA (ultraviolet A) for 10-20%.
Artificial tanning beds use UVA radiation, but do not cause production
of vitamin D3. On the contrary, artificial tanning causes the breakdown
of this vitamin.
Skin
protection and aging caused by the sun