title: Narrowband Ultraviolet B Exposures Maintain Vitamin D Levels During Winter: A Randomized Controlled Trial.
abstract: Exposure to solar ultraviolet B radiation during the summer months is the main source of vitamin D (VD) for people living in northern latitudes. The aim of this study was to determine whether artificial narrowband ultraviolet B (NB-UVB) whole-body exposures could maintain VD levels in winter. The intervention group received 2 standard erythema doses (SEDs) of NB-UVB exposures every second week from October 2013 to April 2014. In October 2013 serum 25-hydroxyvitamin D concentrations were 78.3 nmol/l in the intervention group (n = 16) and 76.8 nmol/l in the control group (n = 18). By April 2014 the concentrations had increased by 11.7 nmol/l (p = 0.029) in the intervention group and decreased by 11.1 nmol/l (p = 0.022) in the control group. The baseline VD concentration showed a negative correlation (p = 0.012) with body mass index (BMI). In conclusion, a suberythemal NB-UVB dose of 2 SED every second week maintains and even increases serum VD concentrations during the winter. A high BMI seems to predispose subjects to low levels of VD.
authors.affiliation: Department of Dermatology, Tampere University Hospital, PO Box 2000, FIN-33521 Tampere, Finland. toni.karppinen@epilaser.fi, karppinen.toni.t@student.uta.fi.
authors.forename: Toni
authors.initials: T
authors.lastname: Karppinen
authors.forename: Meri
authors.initials: M
authors.lastname: Ala-Houhala
authors.forename: Lasse
authors.initials: L
authors.lastname: Ylianttila
authors.forename: Hannu
authors.initials: H
authors.lastname: Kautiainen
authors.forename: Heli
authors.initials: H
authors.lastname: Viljakainen
authors.forename: Timo
authors.initials: T
authors.lastname: Reunala
authors.forename: Erna
authors.initials: E
authors.lastname: Snellman
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D005260:Female; D005387:Finland; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012621:Seasons; D013997:Time Factors; D016896:Treatment Outcome; D014466:Ultraviolet Rays / Q000009:adverse effects; D014467:Ultraviolet Therapy / Q000009:adverse effects / Q000379:methods*; D015854:Up-Regulation; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D