title: Seasonal variations in vitamin D levels in melanoma patients: a single-centre prospective pilot comparative study.
abstract: BACKGROUND
  More than 90% of vitamin D synthesis is dependent on UV exposure. Photosensitive disorders such as lupus erythematosus, protoporphyria and xeroderma require strict sun avoidance, and vitamin D deficiency has been demonstrated in these patients. Melanoma patients are also instructed to avoid sun exposure and may hence be expected to be vitamin D deficient.
  
  
  METHODS
  Winter and summer vitamin D levels were compared in a group of melanoma patients (n =61) and age- and phototype-matched controls (n = 53) without photosensitive disorders.
  
  
  RESULTS
  Oral supplementary vitamin D intake was reported in 32.7% of the melanoma patients and in 15.1% in the control group. Despite oral supplementation, only 25% of the melanoma patients and the controls presented with vitamin D levels of 30 ng/mL or higher. In non-supplemented subjects in the melanoma and control groups, respectively, mean winter vitamin D levels were below the recommended threshold at 12.6 ng/mL vs. 13.2 ng/mL, respectively, but not statistically different. These values increased significantly in both groups during the summer to 24.6 and 23.8 ng/mL respectively.
  
  
  CONCLUSIONS
  Unexpected, significant increases in vitamin D levels were seen in melanoma patients during summer, suggesting non-adherence with photoprotective measures and reflecting a heliophilic behaviour. Vitamin D supplementation is recommended in melanoma patients during both winter and summer.
authors.affiliation: Department of Dermatology, University Hospital Sart Tilman, University of Liège, Liège, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Failla
authors.forename: E
authors.initials: E
authors.lastname: Cavalier
authors.forename: L
authors.initials: L
authors.lastname: El Hayderi
authors.forename: D
authors.initials: D
authors.lastname: Paurobally
authors.forename: J P
authors.initials: JP
authors.lastname: Chapelle
authors.forename: B
authors.initials: B
authors.lastname: Dezfoulian
authors.forename: A F
authors.initials: AF
authors.lastname: Nikkels
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D006801:Humans; D008545:Melanoma / Q000097:blood*; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012621:Seasons; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D