Production of Vitamin D Metabolites by UV-radiation From Solar Bed

Background: Some patients do not readily absorb vitamin D from intestine. These patients may be helped by ultraviolet rays, which can come from sunlight or solar beds. When the skin is exposed to ultraviolet B rays (UVB) vitamin D is produced. This usually happens when the skin is exposed to sunlight. Vitamin D can also be ingested trough some foods, mainly fatty fish or supplements. Vitamin D is important for bone, and long-term vitamin D deficiency can lead to osteoporosis. Vitamin D may also be important for the immune system-including autoimmune diseases-and the cardiovascular system. Purpose: The main purpose of the study is to learn more about the production of vitamin D3 in the skin, by ultraviolet radiation. Study Course: Day 0: Randomization. Subjects are randomized to two groups. Subjects in both groups will be exposed to light in a solar bed for approximately 10 minutes on the first day, but only one of the solar beds wields ultraviolet rays. The other has a filter, which filters out the ultraviolet rays. Blood samples are drawn on the first day at following times: Before solar bed, after at 15 minutes, 1, 2, 4 and 6 hours. Day 1,2,3 and 7 after solar bed exposure: Blood samples are drawn and adverse events are registered.