If you have psoriasis, a little sun can do you a world of good. An effective treatment option for psoriasis is phototherapy or heliotherapy from moderate natural sunlight or sunlamps. Exposing skin with psoriasis to the ultraviolet B or UVB rays from the sun or sun lamps can effectively treat patches of irritated and inflamed psoriasis skin. It is not entirely clear exactly how UVB helps treat psoriasis. It has been shown that UVB can decrease local inflammation, as well as increase vitamin D production in the skin. Vitamin D is an essential nutrient we get from sun exposure, diet and supplements. It regulates the immune system and cellular growth, and vitamin D deficiency can cause many chronic health conditions. Sun treatment in people with psoriasis boosts vitamin D levels and has been shown to ease psoriasis symptoms. If you undergo phototherapy, you should start to see results over several weeks of initiating treatment. However, UVB rays also raise your risk of skin cancer. It is easy to go overboard when self treating at home with sunlamps or lying out at the beach, so it is important to discuss the best approach with your dermatologist. Phototherapy units are an excellent option as they provide disease modifying doses of UVB in a controlled and monitored setting, often in a hospital. Laser treatment is an alternative to natural sunlight and sun lamp exposure. The excimer laser emits a wavelength in the UVB spectrum and can be effective for small areas. The pulsed dye laser has also been shown to be helpful in treating nail psoriasis, which is often a very tricky and disabling form. Another tip - DON'T replace natural sunlight with tanning beds. The beds mostly emit UVA light, which DOESN'T treat your psoriasis. Plus, tanning beds are a known carcinogen-they increase risk of melanoma, or skin cancer, by 75 percent! For more information on psoriasis treatments, watch other videos in this series.