UVB therapy increases 25(OH) vitamin D syntheses in postmenopausal women with psoriasis.
BACKGROUND
Vitamin D3 is produced in the epidermis by ultraviolet (UV) radiation (290-315 nm) of 7-dehydrocholesterol. A similar range of 290-320 nm (broadband UVB) has been successfully used for years to treat psoriasis. The aim of this study was to investigate whether UVB therapy was able to influence vitamin D synthesis in psoriasis patients.


METHODS
Twenty-four postmenopausal, white Caucasian women, aged 69 +/- 5.9 (mean +/- SD), with active plaque psoriasis, were treated with broadband UVB two to three times per week for 8-12 weeks. The serum concentrations of calcidiol (25(OH)D3), calcitriol (1,25(OH)2D3), intact parathyroid hormone (PTH), thyroid hormones, osteocalcin, calcium and creatinine were measured before the first and after the last dose of radiation. Bone density was measured using Dual-Energy X-ray Absorptiometry (Hologic Delphi A) at the hip and lumbar spine.


RESULTS
Serum levels of 25(OH)D3 increased from 36.8 +/- 17 ng/ml (mean +/- SD) to 59.6 +/- 18.7 ng/ml (P<0.001) after the UVB treatment period. Serum PTH decreased from 62.8 +/- 25.7 ng/l to 48.2 +/- 17.4 ng/l (P<0.001). Secondary hyperparathyroidism (PTH>65 ng/l) was revealed in seven patients (29%) in whom PTH values were suppressed by the UVB therapy. The serum levels of calcitriol, calcium, osteocalcin, thyroid hormones and creatinine were unaltered.


CONCLUSIONS
UVB therapy in elderly psoriatic women improved psoriasis, increased serum 25(OH)D3 synthesis and reduced serum PTH concentrations.
Osmancevic
Amra
A
Department of Dermatology, Sahlgrenska University Hospital, Göteborg, Sweden. Amra.Osmancevic@vgregion.se
Landin-Wilhelmsen
Kerstin
K
Larkö
Olle
O
Mellström
Dan
D
Wennberg
Ann-Marie
AM
Hulthén
Lena
L
Krogstad
Anne-Lene
AL
D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D015992:Body Mass Index; D002112:Calcifediol / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000378:metabolism; D010789:Phototherapy; D017698:Postmenopause; D011565:Psoriasis / Q000378:metabolism*; D014466:Ultraviolet Rays