A Narrow-Band Ultraviolet B Course Improves Vitamin D Balance and Alters Cutaneous CYP27A1 and CYP27B1 mRNA Expression Levels in Haemodialysis Patients Supplemented with Oral Vitamin D

作者：Ala Houhala Meri J^*; Vahavihu Katja; Snellman Erna; Hasan Taina; Kautiainen Hannu; Karisola Piia; Dombrowski Yvonne; Schauber Juergen; Saha Heikki; Reunala Timo

来源：Nephron Clinical Practice, 2013, 124(1-2): 17-22.

DOI：10.1159/000355010

• Cholecalciferol
• Chronic kidney disease
• CYP27A1
• CYP27B1
• Haemodialysis
• Ultraviolet B radiation
• Vitamin D

Background/Aims: Chronic kidney disease (CKD) patients on dialysis are prone to vitamin D insufficiency despite oral vitamin D supplementation. Here, we studied whether narrow-band ultraviolet B (NB-UVB) exposures improve vitamin D balance. Methods: 14 haemodialysis patients and 15 healthy subjects receiving oral cholecalciferol 20 mu g daily got nine NB-UVB exposures on the entire body. Serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay. Cutaneous mRNA expression levels of CYP27A1 and CYP27B1, two enzymes required for hydroxylation of vitamin D into its active metabolite, were also measured. Results: The baseline serum 25(OH)D concentration was 57.6 +/- 18.2 nmol/l in the CKD patients and 74.3 +/- 14.8 nmol/l in the healthy subjects. The NB-UVB course increased serum 25(OH)D by 14.0 nmol/l (95% CI 8.7-19.5) and 17.0 nmol/l (CI 13.7-20.2), respectively. At baseline the CKD patients showed significantly increased CYP27B1 levels compared to the healthy subjects. Conclusions: A short NB-UVB course is an efficient way to improve vitamin D balance in CKD patients on dialysis who are receiving oral vitamin D supplementation. The increased cutaneous CYP27B1 levels in the CKD patients suggest that the loss of renal activity of this enzyme is at least partially compensated for by the skin.

• 出版日期2013