En stor del av personalen inom Hälso- och Sjukvården har sin arbetstid förlagd till natten. Vi vet idag att det är mycket ogynnsamt att arbeta nattetid och att det höjer risken att utveckla flera sjukdomar. Nattarbete och roterande skiftarbete stör och påverkar den naturliga dygnsrytmen i kroppen. Kan vi hjälpa kroppen att anpassa sig bättre till nattskiftsarbete med hjälp av ljusterapins effekter? Ljusterapi är, vad vi känner till idag, en säker behandling med få eller inga biverkningar.

Background: Sweden is a country where vitamin D deficiency seems to be common, partly because of its geographical position, which reduces the availability of UVB radiation, but also that people avoid sunlight due to increased skin cancer risk. Research shows that vitamin D plays an important role in the prevention of many diseases such as cancer as well as autoimmune and neuropsychiatric diseases.Vitamin D is a fat soluble pre-hormone and a collective name for closely related compounds which act as hormones after undergoing a transformation in the body.Humans can utilize vitamin D through diet and produce it in the body by exposing the skin to the sun. Previous observational studies and epidemiological studies have established a hypothesis that there seems to be an association between vitamin D supplementation and reduction of depressive symptoms.Objective: The aim of this study was to investigate if vitamin D supplements may decrease depressive symptoms.Methods: This work is organized as a literature review and article search is made in the database PubMed in January 2012. Keywords used were ?vitamin D and depression? and inclusion criteria were: randomized clinical trials, be conducted on humans, written in English.