title: 25-Hydroxyvitamin D levels in African-American and Caucasian/Hispanic subjects with cutaneous lupus erythematosus.
abstract: BACKGROUND
  Because exposure to ultraviolet radiation accounts for a significant portion of endogenous vitamin D production, subjects with cutaneous lupus (CLE) who practise sun-protective measures are at risk for vitamin D insufficiency. Previous studies have shown light-skinned subjects with CLE to have lower serum 25-hydroxy (25-OH) vitamin D levels than normal controls.
  
  
  OBJECTIVE
  To assess the status of vitamin D insufficiency in dark-skinned individuals with CLE.
  
  
  METHODS
  We performed a cross-sectional study comparing serum 25-OH vitamin D levels in 25 African-American (AA) subjects with CLE and 26 normal AA subjects matched by age, sex and season in Dallas, Texas. A questionnaire on demographics, medical history and lifestyle habits was administered to determine factors potentially affecting vitamin D levels. Findings were contrasted to a similar comparison in 26 Caucasian and Hispanic (C/H) subjects with CLE and 24 normal C/H subjects matched by age, sex and season.
  
  
  RESULTS
  We found similar mean±SD 25-OH vitamin D levels in AA subjects with CLE (52·0±18·5nmolL(-1) ) and normal AA subjects (54·8±21·2 nmolL(-1) ) (P=0·62). Almost half of AA subjects in both groups were vitamin D insufficient. A larger difference in 25-OH vitamin D levels was found between C/H subjects with CLE (59·4±21·0nmolL(-1) ) and normal C/H subjects (70·5±27·4nmolL(-1) ) (P=0·12). Two-way anova demonstrated that skin colour (AA vs. C/H) had a significant effect on 25-OH vitamin D levels (P=0·008), although CLE status (CLE vs. normal) did not (P=0·13).
  
  
  CONCLUSIONS
  Providers are encouraged to address vitamin D insufficiency concerns in all dark-skinned individuals. Future studies should stratify subjects by skin colour in determining differences between subjects with CLE and normal controls.
authors.affiliation: Departments of Dermatology and Clinical Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Word
authors.forename: F
authors.initials: F
authors.lastname: Perese
authors.forename: L-C
authors.initials: LC
authors.lastname: Tseng
authors.forename: B
authors.initials: B
authors.lastname: Adams-Huet
authors.forename: N J
authors.initials: NJ
authors.lastname: Olsen
authors.forename: B F
authors.initials: BF
authors.lastname: Chong
mesh_terms: D000328:Adult; D001741:Black or African American / Q000208:ethnology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006630:Hispanic or Latino / Q000208:ethnology*; D006801:Humans; D008019:Life Style; D008178:Lupus Erythematosus, Cutaneous / Q000208:ethnology*; D008297:Male; D008875:Middle Aged; D012621:Seasons; D012880:Skin Pigmentation; D013471:Sunburn / Q000517:prevention & control; D013473:Sunscreening Agents / Q000627:therapeutic use; D013781:Texas / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000208:ethnology*; D044465:White People / Q000208:ethnology*
chemical_list: D013473:Sunscreening Agents; D014807:Vitamin D; C104450:25-hydroxyvitamin D