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Vitamin D production after UVB exposure – A comparison of exposed skin regions – Feb 2015

J. of Photochemistry and Photobiology B: Biology. Vol 143, Feb 2015, Pages 38-43. https://doi.org/10.1016/j.jphotobiol.2014.12.026
mra Osmancevica Katarina Sandströma Martin Gillstedta Kerstin Landin-WilhelmsenbOlle Larköa Ann-MarieWennberg Larköa MichaelF. Holick Anne-Lene Krogstadad
Image
The figure shows the increase in 25-hydroxyvitamin D3 [25(OH)D3] during the UVB exposures of 3 different skin areas. Each point depicts one participant during the UVB exposures (before and 24 h after the 3 exposures for one skin region). Horizontal bars are median values.

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Highlights

  • Serum cholecalciferol and 25(OH)D3 increased after UVB irradiation of 3 different anatomic sites in the same individuals.
  • UVB exposure of a larger skin area resulted in greater increases in serum cholecalciferol concentrations.
  • Sporadic exposure of only face and hands was capable of a significant rise in serum concentrations of 25(OH)D3

Background
Cholecalciferol is an essential steroid produced in the skin by solar ultraviolet B radiation (UVB 290–315 nm). Skin production of cholecalciferol depends on factors affecting UVB flux, age and exposed skin area.

Purpose
Serum cholecalciferol and 25-hydroxyvitamin D3 [25(OH)D3] concentrations were measured after UVB irradiation of 3 different skin areas to compare the skin capacity to produce vitamin D in different anatomic sites in the same individuals.

Method
Ten voluntary Caucasians (skin photo type II & III, aged 48 ± 12 years (±SD)) were exposed to broadband UVB (280–320 nm) between February and April. Hands and face, upper body and whole body were exposed to a suberythemic dose of UVB (median 101 mJ/cm2 (min 66, max 143)) (for 3 subsequent days 24 h apart with a wash out period of about 3 weeks (median 18 days (min 11, max 25)) between the exposures of respective area. Serum concentrations of cholecalciferol and 25(OH)D3, were measured immediately before the first and 24 h after the last dose of radiation.

Results
There was a significantly higher increase in serum cholecalciferol after UVB exposure of the two larger skin areas compared to face and hands, but no difference in increase was found between upper body and whole body exposures.

Conclusion
Exposure of a larger skin area was superior to small areas and gave greater increase in both serum cholecalciferol and serum 25(OH)D3 concentrations. However, exposure of face and hands, i.e. only 5% of the body surface area, was capable of increasing serum concentrations of 25(OH)D3.


Cited by 29 publications as of May 2021


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15639 increased D.jpg admin 25 May, 2021 17:51 21.32 Kb 74
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