title: Short-term UVB irradiation significantly increases vitamin D serum concentration in obese patients: a clinical pilot study.
abstract: OBJECTIVE
  Deficiency of vitamin D is very common in obese people and treatment by oral supplementation is not effective in all patients. This exploratory pilot study investigated the influence of different doses of short-term ultraviolet B irradiation on serum 25-hydroxyvitamin-D3(25D) and 1,25-dihydroxyvitamin-D3(1,25D) levels in obese compared to normal weight subjects and obese controls.
  
  
  METHODS
  Participants with skin types II and III (Fitzpatrick skin classification) were assigned to six groups including four intervention groups receiving irradiation (three groups of obese and one group of normal weight subjects) and two control groups without treatment (obese and normal weight). Intervention groups received three sessions of whole body UVB irradiation of three different doses (cumulative doses over three sessions: 0.28, 0.70, 1.75 minimal erythema dose) within 1 week of intervention. Serum 25D and 1,25D were measured at baseline and after irradiation. Outcome differences between groups were analyzed using a linear model.
  
  
  RESULTS
  Serum 25D levels increased significantly in obese (+23.6 and +26.7%, respectively, p = 0.01) and normal weight (+15.6%, p = 0.02) intervention groups who received medium and high doses of ultraviolet B irradiation compared to control groups (+3.5 and -4.0%, respectively, p = 1.0). The increase in obese patients was 51.4% greater compared to normal weight controls irradiated with equal ultraviolet B doses. Low-level ultraviolet irradiation did not result in a significant change in serum 25D (+7.0%, p = 0.61). We did not detect any significant differences of 1,25D between groups (p = 0.25).
  
  
  CONCLUSIONS
  The current study indicates that short-term ultraviolet B irradiation increases 25D levels in obese patients.
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany. alexander.obbarius@charite.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Obbarius
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Berger
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stengel
authors.affiliation: Sleep Medicine Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcia
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Fischer
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hofmann
authors.affiliation: Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rose
authors.affiliation: Medical Photobiology Group, Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, 10117, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Uebelhack
mesh_terms: D000328:Adult; D002112:Calcifediol / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications; D010865:Pilot Projects; D014466:Ultraviolet Rays; D014467:Ultraviolet Therapy / Q000379:methods*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications / Q000628:therapy*
chemical_list: C118756:dihydroxy-vitamin D3; D014807:Vitamin D; D002112:Calcifediol
keywords: 1,25-Dihydroxyvitamin-D3; 25-Hydroxyvitamin-D3; Non-randomized controlled clinical trial; Obesity; UVB irradiation; Vitamin D