The Effect of Narrowband Ultraviolet B Phototherapy on Vitamin D Status in Psoriasis Patients with Skin Phototype III, IV and V

ABSTRACT

Background@#Narrowband ultraviolet-B (NBUVB) is an effective treatment option for psoriasis. Vitamin D insufficiency is common in psoriasis patients. We assessed the effect of NBUVB on vitamin D levels amongst psoriasis patients with skin phototype III, IV and V.@*Methods@#Psoriasis patients planned for NBUVB phototherapy were enrolled in a prospective cohort study in Hospital Putrajaya and Hospital Kuala Lumpur from May 2020-December 2020. NBUVB phototherapy was given twice weekly for 12 weeks. Serum 25 (OH)D level was measured at baseline and at week 12.@*Results@#A total of 21(63.6%) male and 12(36.4%) female patients aged 18-66 years participated. Majority were Fitzpatrick skin phototype (FSP) IV (66.7%) followed by FSP V (21.2%) and FSP III (12.1%). Serum 25(OH)D increased significantly (p<0.001) from 52.09±21.43 nmol/L at baseline to 72.80±19.56 nmol/L at week 12 with the most increment seen in skin type V. There was also a significant improvement seen in Body Surface Area (BSA) involvement after 12 weeks of phototherapy (p<0.001). There was no correlation seen between BSA at week 12 with serum 25(OH)D and percentage of serum 25(OH) D increment.@*Conclusion@#NBUVB phototherapy increases the level of serum 25(OH)D in psoriasis patients with darker skin types while simultaneously clearing psoriasis.