The effect of narrowband UV-B treatment for psoriasis on vitamin D status during wintertime in Ireland.
OBJECTIVE
To determine whether narrowband UV-B (NB-UV-B) may mediate its beneficial effect on psoriasis by increasing vitamin D levels, and to assess the effect of NB-UV-B on vitamin D status in patients with psoriasis in wintertime.


METHODS
A prospective controlled study from October 2008 to February 2009.


METHODS
A dermatology outpatient department at a university teaching hospital.


METHODS
Thirty consecutive patients with psoriasis treated with NB-UV-B and 30 control patients with psoriasis were recruited. Control patients were recruited within 1 week of treated patients to control for seasonal variation of serum 25-hydroxyvitamin D [25(OH)D] levels. One patient with photo aggravated psoriasis was withdrawn from the study.


METHODS
Narrowband UV-B was administered 3 times per week.


METHODS
Serum 25(OH)D was measured at baseline, after 4 weeks and at completion of treatment.


RESULTS
Levels of serum 25(OH)D increased significantly(P< .001) from a median (range) of 23 (9-46)ng/mL at baseline to 51 [rather than 59, as given in the originally published article] (32-112) ng/mL at the end of NB–UV-B treatment compared with no change in the control group [corrected]. The change in serum 25(OH)D level correlated with the number of exposures of NB-UV-B (r = 0.61; P < .001) and cumulative UV-B dose (r = 0.47; P = .01) but not with treatment response. At the end of the study, all patients in the treatment group were vitamin D sufficient, but 75% of the control group had vitamin D insufficiency [serum 25(OH)D level <20 ng/mL]. In a multiple regression model, prior phototherapy was the sole predictor of baseline serum 25(OH)D level (r(2) = 0.13; P = .006), whereas the number of exposures of NB-UV-B predicted change in serum 25(OH)D level (r(2) = 0.38; P = .001).


CONCLUSIONS
Narrowband UV-B effectively increases serum 25(OH)D level while clearing psoriasis. Up to 75% of Irish patients with psoriasis were shown to be vitamin D insufficient during wintertime.
Ryan
Caitriona
C
Baylor Research Institute, 3900 Junius Street, Dallas, TX 75246, USA. Caitriona.ryan@baylorhealth.edu
Moran
Benvon
B
McKenna
Malachi J
MJ
Murray
Barbara F
BF
Brady
Jennifer
J
Collins
Paul
P
Rogers
Sarah
S
Kirby
Brian
B
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011565:Psoriasis / Q000532:radiotherapy*; D012044:Regression Analysis; D012621:Seasons; D016896:Treatment Outcome; D014467:Ultraviolet Therapy / Q000379:methods*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000528:radiation effects; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000532:radiotherapy*; D055815:Young Adult
D014807:Vitamin D; C104450:25-hydroxyvitamin D