Loading...
 
Toggle Health Problems and D

UVA decreased serum levels of vitamin D - RCT Oct 2012

Changes in serum 25-hydroxyvitamin D and cholecalciferol after one whole-body exposure in a commercial tanning bed: a randomized study.

Endocrine. 2012 Oct;42(2):430-5. Epub 2012 Mar 6.
Langdahl JH, Schierbeck LL, Bang UC, Jensen JE.
Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.

We wanted to evaluate the cutaneous synthesis of 25OHD and cholecalciferol after one whole-body exposure to ultraviolet radiation type B (UVB) in a randomized setup. Healthy volunteers were randomized to one whole-body exposure in a commercial tanning bed with UVB emission (UVB/UVA ratio 1.8-2.0%) or an identical placebo tanning bed without UVB. The output in the 280-320 nm range was 450 µW/cm². Blood samples were analyzed for 25OHD and cholecalciferol at baseline and during 7 days after treatment.

We included 20 volunteers, 11 to UVB and 9 to placebo treatment. During the first 6 h, no significant differences in 25OHD between the groups were found. At the end of the study, we found a mean increase of 25OHD in the UVB group of 4.5 nmol/l (SD 7 nmol/l) compared to a decline of -1.2 nmol/l (SD 7 nmol/l) in the placebo group (p = 0.1). A linear mixed model yielded an increase of 25OHD in the UVB group of 1.0 nmol/l per 24 h (p < 0.01). For cholecalciferol, we found a near significant increase of 1 pmol/l per hour in the UVB group compared to the placebo group during the first 6 h (p = 0.052). One tanning bed session had significant, but modest impact on the level of 25OHD during 7 days after exposure to UVB.

PMID: 22391940

Details: yellow = no UVB

Notice: Frequently (but not always) getting just UVA DECREASED the vitamin D levels.
Image

Spectrum of one of the bulbs

Image

References

  1. K. Ukinc, Severe osteomalacia presenting with multiple vertebral fractures: a case report and review of the literature. Endocrine 36, 30–36 (2009) CrossRef
  2. G. Mazziotti, J. Bilezikian, E. Canalis, D. Cocchi, A. Giustina, New understanding and treatments for osteoporosis. Endocrine 41, 58–69 (2012) CrossRef
  3. N.C. Bozkurt, E. Cakal, M. Sahin, E.C. Ozkaya, H. Firat, T. Delibasi, The relation of serum 25-hydroxyvitamin-D levels with severity of obstructive sleep apnea and glucose metabolism abnormalities. Endocrine. (2012). doi:10.1007/s12020-012-9595-1
  4. M. Chung, with or without calcium supplementation for prevention of cancer and fractures: an updated meta-analysis for the U.S. Preventive Services Task Force. Ann. Intern. Med. 155, 827–838 (2011)
  5. J. McGrath, A. Brown, St CD, Prevention and schizophrenia—the role of dietary factors. Schizophr. Bull. 37, 272–283 (2011) CrossRef
  6. M.F. Holick, Vitamin D deficiency. N. Engl. J. Med. 357, 266–281 (2007) CrossRef
  7. M.F. Holick, N.M. Richtand, S.C. McNeill, S.A. Holick, J.E. Frommer, J.W. Henley, J.T. Potts Jr, Isolation and identification of previtamin D3 from the skin of rats exposed to ultraviolet irradiation. Biochemistry 18, 1003–1008 (1979) CrossRef
  8. M.F. Holick, J.A. MacLaughlin, S.H. Doppelt, Regulation of cutaneous previtamin D3 photosynthesis in man: skin pigment is not an essential regulator. Science 211, 590–593 (1981) CrossRef
  9. J. MacLaughlin, M.F. Holick, Aging decreases the capacity of human skin to produce vitamin D3. J. Clin. Invest. 76, 1536–1538 (1985) CrossRef
  10. A.R. Webb, O. Engelsen, Calculated ultraviolet exposure levels for a healthy vitamin D status. Photochem. Photobiol. 82, 1697–1703 (2006)
  11. A.R. Webb, H. Slaper, P. Koepke, A.W. Schmalwieser, Know your standard: clarifying the CIE erythema action spectrum. Photochem. Photobiol. 87, 483–486 (2011) CrossRef
  12. H.W. Randle, Suntanning: differences in perceptions throughout history. Mayo Clin. Proc. 72, 461–466 (1997) CrossRef
  13. J.S. Adams, T.L. Clemens, J.A. Parrish, M.F. Holick, Vitamin-D synthesis and metabolism after ultraviolet irradiation of normal and vitamin-D-deficient subjects. N. Engl. J. Med. 306, 722–725 (1982) CrossRef
  14. L.A. Armas, S. Dowell, M. Akhter, S. Duthuluru, C. Huerter, B.W. Hollis, R. Lund, R.P. Heaney, Ultraviolet-B radiation increases serum 25-hydroxyvitamin D levels: the effect of UVB dose and skin color. J. Am. Acad. Dermatol. 57, 588–593 (2007) CrossRef
  15. E. Thieden, H.L. Jorgensen, N.R. Jorgensen, P.A. Philipsen, H.C. Wulf, Sunbed radiation provokes cutaneous vitamin D synthesis in humans—a randomized controlled trial. Photochem. Photobiol. 84, 1487–1492 (2008) CrossRef
  16. Commission Internationale de l’Eclairage (CIE). Action spectrum for the production of previtamin D3 in human skin. 174 edn. (2006), pp. 1–12
  17. T.B. Fitzpatrick, The validity and practicality of sun-reactive skin types I through VI. Arch. Dermatol. 124, 869–871 (1988) CrossRef
  18. B.L. Diffey, C.T. Jansen, F. Urbach, H.C. Wulf, The standard erythema dose: a new photobiological concept. Photodermatol. Photoimmunol. Photomed. 13, 64–66 (1997) CrossRef
  19. R.D. Ley, L.A. Applegate, R.J. Fry, A.B. Sanchez, Photoreactivation of ultraviolet radiation-induced skin and eye tumors of Monodelphis domestica. Cancer Res. 51, 6539–6542 (1991)
  20. T.L. Clemens, J.S. Adams, S.L. Henderson, M.F. Holick, Increased skin pigment reduces the capacity of skin to synthesise vitamin D3. Lancet 1, 74–76 (1982) CrossRef
  21. M.D. Farrar, R. Kift, S.J. Felton, J.L. Berry, M.T. Durkin, D. Allan, A. Vail, A.R. Webb, L.E. Rhodes, Recommended summer sunlight exposure amounts fail to produce sufficient vitamin D status in UK adults of South Asian origin. Am. J. Clin. Nutr. 94, 1219–1224 (2011) CrossRef
  22. L.Y. Matsuoka, J. Wortsman, J.G. Haddad, P. Kolm, B.W. Hollis, Racial pigmentation and the cutaneous synthesis of vitamin D. Arch. Dermatol. 127, 536–538 (1991) CrossRef

Comments by VitaminDWiki

  • UVA destroys Vitamin D in the body (many previous hints of this)
    • Window glass block most of UVA, but ALL of UVB - thus getting UV thru glass appears to decrease your levels of vitamin D
    • This may be one of the reasons that truckers live much shorter lives: UVA without UVB ==> lowering of vitamin D levels
  • UVA + UVB: net increase in blood levels of vitamin D
  • UVB only: larger net increase (a single hint that it might be 6x this has not been confirmed)
    • Some bulbs have just UVB
  • There is a way to block all but UVB:i.e. block UVA and visible and IR (Heat) - see below

See VitaminDWiki

uv window glass.jpg

Attached files

ID Name Comment Uploaded Size Downloads
14081 UV Holick 1982.pdf admin 26 Jul, 2020 670.43 Kb 569
2306 Tanning markup.pdf admin 06 Apr, 2013 103.45 Kb 1559
2305 Tanning bulbs.pdf admin 06 Apr, 2013 192.05 Kb 939
2304 tanning RCT.jpg admin 06 Apr, 2013 162.82 Kb 2199
2303 Tanning RCT bulb.jpg admin 06 Apr, 2013 32.75 Kb 1893