Original sentence: "  This mood elevation may make tanning addictive for a some people.Exposure to UV light (regardless of source) leads to production of vitamin D in the skin.In some extreme circumstances the purchase of home tanning beds have even been prescribed by doctors and is covered by many insurance policies.It is commonly believed that indoor tanning beds are useful for the treatment of SAD (Seasonal_Affective_Disorder), although this has been disputed.More commonly, many people with psoriasis, eczema or other skin disorders are regularly treated with UV to lessen the symptoms and tanning beds can be one option for individuals with moderate skin problems.UV exposure causes the body to release endorphins, which may be why people may experience temporary mood elevation similar to a "runners high.While a tan that is developed in a tanning bed does offer some protection from overexposure, it is more cosmetic than a natural tan and does not offer the same level of protection, so SPF should be used for extended periods outside, even if the individual is wanting to increase their tan
Edited sentence: "  This mood elevation may make tanning addictive for some people.First, exposure to UV light leads to  production of vitamin D in the skin.There are benefits from exposure to UV light, though many of these benefits can be achieved without the risks associated with tanning.UV exposure is known to cause the body to release endorphins, which may be why people may experience temporary mood elevation similar to a "runners high