title: Tanning is associated with optimal vitamin D status (serum 25-hydroxyvitamin D concentration) and higher bone mineral density.
abstract: BACKGROUND
  Vitamin D is made in the skin on exposure to solar radiation, and it is necessary to optimal skeletal health. Subjects who use a tanning bed that emits ultraviolet B radiation (290-315 nm) are likely to have higher 25-hydroxyvitamin D [25(OH)D] concentrations than do subjects who do not regularly use a tanning bed.
  
  
  OBJECTIVE
  The first objective of this study was to ascertain whether subjects who regularly use a tanning bed have higher 25(OH)D concentrations than do subjects who do not use a tanning bed. The second objective was to ascertain whether higher 25(OH)D concentrations correlated positively with bone mineral density.
  
  
  METHODS
  This cross-sectional analysis examined 50 subjects who used a tanning bed at least once a week and 106 control subjects. Each subject gave a blood specimen for measurement of serum 25(OH)D and parathyroid hormone concentrations. Each subject underwent bone mineral density testing of the hip and spine.
  
  
  RESULTS
  Subjects who used a tanning bed had serum 25(OH)D concentrations 90% higher than those of control subjects (115.5 +/- 8.0 and 60.3 +/- 3.0 nmol/L, respectively; P <0.001). Subjects who used a tanning bed had parathyroid hormone concentrations 18% lower than those of control subjects (21.4 +/- 1.0 and 25.3 +/- 0.8 pg/mL, respectively; P=0.01). Tanners had significantly higher BMD and z scores at the total hip than did nontanners.
  
  
  CONCLUSIONS
  The regular use of a tanning bed that emits vitamin D-producing ultraviolet radiation is associated with higher 25(OH)D concentrations and thus may have a benefit for the skeleton.
authors.affiliation: Vitamin D, Skin and Bone Research Laboratory and the Section of Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Vin
authors.initials: V
authors.lastname: Tangpricha
authors.forename: Adrian
authors.initials: A
authors.lastname: Turner
authors.forename: Catherine
authors.initials: C
authors.lastname: Spina
authors.forename: Sheila
authors.initials: S
authors.lastname: Decastro
authors.forename: Tai C
authors.initials: TC
authors.lastname: Chen
authors.forename: Michael F
authors.initials: MF
authors.lastname: Holick
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D015519:Bone Density / Q000502:physiology* / Q000528:radiation effects; D001842:Bone and Bones / Q000378:metabolism / Q000528:radiation effects*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood; D012621:Seasons; D013131:Spine / Q000000981:diagnostic imaging; D013472:Sunlight; D014466:Ultraviolet Rays; D014481:United States; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood* / Q000378:metabolism / Q000528:radiation effects*; D014808:Vitamin D Deficiency / Q000453:epidemiology
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D