title: Narrowband ultraviolet B phototherapy does not influence serum and red cell folate levels in patients with psoriasis.
abstract: BACKGROUND
  Narrowband ultraviolet (UV) B phototherapy (nbUVB) is a widely used modality in the treatment of psoriasis and is generally accepted to be safe in pregnancy. Previous studies have described photodegradation of serum folate after exposure to UVA radiation but the effect of UVB is not known. Insufficient folate levels predispose to neural tube defects in pregnancy. In addition, folate deficiency may increase the risk of colorectal carcinoma and influence serum homocysteine levels, which are thought to be a risk factor for cardiovascular disease.
  
  
  OBJECTIVE
  We sought to determine whether exposure to nbUVB reduces folate levels.
  
  
  METHODS
  This single-center, open observational study was conducted in a teaching hospital setting. Serum and red cell folate levels were measured in patients with psoriasis attending for nbUVB at baseline and after a minimum of 18 exposures.
  
  
  RESULTS
  A total of 35 patients completed the study. Mean serum and red cell folate levels at baseline were 6.34 and 410 ng/ml, respectively. After nbUVB, mean serum and red cell folate levels were 6.35 and 423 ng/ml, respectively. This was not significantly different from baseline measurements (P = .99 serum folate and P = .57 red cell folate).
  
  
  CONCLUSIONS
  This study examined the effect of a standard course of 18 exposures of nbUVB on folate levels, rather than prolonged treatment. Adult patients with psoriasis only were investigated.
  
  
  CONCLUSIONS
  A standard course of nbUVB does not have an effect on serum and red cell folate levels in patients with psoriasis.
authors.affiliation: Department of Dermatology at The General Infirmary at Leeds, Great George St, Leeds LS1 3EX, United Kingdom. beckyrose@doctors.org.uk
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Rose
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Batchelor
authors.forename: David
authors.initials: D
authors.lastname: Turner
authors.forename: Victoria
authors.initials: V
authors.lastname: Goulden
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D005492:Folic Acid / Q000097:blood* / Q000378:metabolism; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D011565:Psoriasis / Q000097:blood* / Q000175:diagnosis / Q000532:radiotherapy*; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014467:Ultraviolet Therapy / Q000379:methods*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005492:Folic Acid