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
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.
Seems strange that
- whole body is less than upper body
- face and hands is similar to whole body
Items in both categories Virus and UV are listed here:
- 11 percent fewer COVID-19 deaths if lockdowns had allowed sunshine – Nov 2021
- COVID-19 deaths - 30 percent fewer if high UVA (US, etc) – Aug 2021
- 4th highest county in the US has a very low COVID-19 rate (high UV, high vitamin D)
- COVID-19 onset strongly associated with latitude in Europe (Vitamin D)– Jan 21, 2021
- UV provides the best explanation of COVID-19 variation in Italy (74 pcnt) – Nov 2020
- More UVB, less Coronavirus – including SARS-CoV-2 – Aug 2020
- Less COVID-19 at high altitude due to more Vitamin D or other possible reasons – July 2020
- Far fewer COVID-19 deaths in the summer (Europe, Canada)
- High-altitude Cusco, Peru has far lower rate of COVID-19 than others (high UVB and Vitamin D) - June 2020
- Influenza Virus aerosols killed by 10 minutes of sunlight (far faster if use UV-C) – Nov 2019
- Influenza Virus aerosols killed by 10 minutes of sunlight (faster if use UVB, UVCC– Nov 2019
- Ultraviolet light kills cold and flu viruses, and generates Vitamin D in the skin
- 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
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.
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.
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.
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.
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.