UVB increases vitamin D even if poor kidney by changing CYP27B1 genes in skin – Dec 2013

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.

Nephron Clin Pract. 2013;124(1-2):17-22. doi: 10.1159/000355010. Epub 2013 Sep 12.
Ala-Houhala MJ1, Vähävihu K, Snellman E, Hasan T, Kautiainen H, Karisola P, Dombrowski Y, Schauber J, Saha H, Reunala T.
Department of Dermatology, Tampere University Hospital, Tampere, Finland

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 µg 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.

Copyright © 2013 S. Karger AG, Basel.Wants $38 for the PDF

PMID: 24029861

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Overview and comments by VitaminDWiki

• It appears that the two groups had been supplementing with 800 IU of vitamin D for a long time.
  VitaminDWiki finds it amazing that such a low level was used – especially with dialysis which further decreases vitamin D levels
• Those with chronic kidney disease had lower level of vitamin D: 23 ng vs 30 ng – understandable since kidney is the primary means to activate vitamin D
• Narrowband UVB was added, increasing levels by 5.6 ng and 6.8 ng respectively

See also VitaminDWiki

• UVB improved vitamin D levels in 3 diseases, controls improved more – PHD Nov 2013 PHD dissertation by one of the authors of this study
• UVB effects on genes of those with and without Psoriasis – April 2014
• Ultraviolet light (which produces vitamin D) decreased the use of psoriasis drugs for a year – Aug 2017
• Search VitaminDWiki for CYP27A1 KIDNEY 89 hits as of Aug 2014
• 63 items in CYP27B1 category