Minimum Exposure Limits and Measured Relationships Between the Vitamin D, Erythema and International Commission on Non-Ionizing Radiation Protection Solar Ultraviolet
Photochemistry and Photobiology. DOI: 10.1111/php.12394
Nathan Downs 1,2,3,*, Alfio Parisi 1,3, Harry Butler 1,3, Joanna Turner 1,3 and Lisa Wainwright
The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for exposure to ultraviolet radiation in outdoor occupational settings.
Spectrally weighted ICNIRP ultraviolet exposures received by the skin or eye in an 8 hr period are limited to 30 Jm−2.
In this study, the time required to reach the ICNIRP exposure limit was measured daily in ten minute intervals upon a horizontal plane at a subtropical Australian latitude over a full year and compared with the effective Vitamin D dose received to ¼ of the available skin surface area for all six Fitzpatrick skin types. The comparison of measured solar ultraviolet exposures for the full range of sky conditions in the 2009 measurement period, including a major September continental dust event, show a clear relationship between the weighted ICNIRP and the effective vitamin D dose. Our results show that the horizontal plane ICNIRP ultraviolet exposure may be used under these conditions to provide minimum guidelines for the healthy moderation of vitamin D, scalable to each of the six Fitzpatrick skin types.
VitaminDWiki rented the PDF and extracted the following
Skin type 1 (Whitest) lying down (Full body?)
UV index (3-6) 9,400 IU in 19 minutes
UV Index ( <3) 10,300 IU in 73 minutes
Need more sun as you get older
Need 17% more for age 22-40
Need 34% more for age 41-59
Need 49% more for age > 59
Darker skins need more sun
Type 1 Always burns 200-300 J/m2
Type III Burns moderately 450-600 J/m2
Type VI Never Burns 1000-2000 J/m2 (about 5X more time in the sun)
Examples for lie down, full body, black senior to get 10,000 IU
UV Index <3 730 minutes = impossible (73 minute * 2 * 5)
UV Index 3-6: About 3 hours (19 minute * 2 *5)
Need more sun if you are standing up
Note: It is not clear that more skin ==> more vitamin D: it may be a non-linear relationship
also - some parts of the body may produce more vitamin D than other parts of the body
- perhaps the face produces far more than the pelvis (body may learn)
See also VitaminDWiki
- No – 10 minutes per day of sun-UVB is NOT enough has the following
Time in the sun to get 4000 IU
- Optimize vitamin D from the sun
- 20 cent vitamin D pill similar to 2 hours sunbathing at 60 degree latitude – RCT Aug 2013
- Less Solar Radiation was associated with more Cancer - 1941
- Vitamin D protects DNA against UV skin damage – 5 studies 2012-2013
Also - the higher the level of vitamin D, the less likely you are to get a sun burn - Survey finds that Non-Caucasians do not feel that people need sun exposure – July 2012
- Whites were 2X more likely to be vitamin D deficient if wear long sleeves – Jan 2012
- Getting Vitamin D into your body The sun is one of about 20 ways in increase vitamin D levels
- Cancer Council of Australia recommends 30 minutes of daily sunshine – June 2014
You can see from the current study (from Austrailia) that need more minutes if elderly, dark skin, obese, standing, etc - Obesity category listing with associated searches - click on chart for details
Obese need 2 - 3 X more vitamin D
- Overview Skin and vitamin D which has the following chart - UV while STANDING
- Notional graph of vitamin D vs a few variables
- Vitamin D from the sun vs time of day which has the following graphic