Teens spend so much time with multimedia without the sun

A higher percentage of teens are deficient now than even a decade ago - with major health consequences

Methods to replace the vitamin D from lack of sun include:

1. get outdoors – but hard to change any person’s behavior
   But being outdoors not help much if any of the following:
     cloudy, not middle of the day, dark skin, sun screen, wear excessive clothes, winter and far from equator
2. get vitamin D supplements – but hard to change any person’s behavior
3. Use food fortified with vitamin D – but will take decades to change fortification around the world
4. Have mothers (perhaps secretly) add vitamin D to their food
   drops, pulverized sublingual, powder (no product available as of Feb 2012), etc.
   Somewhat similar to giving cod-liver oil ( a good source of Vitamin D and Vitamin A) a century ago, but fortunately vitamin D has no taste
5. Have a small UVB LED attached to their multimedia device/laptop

Notes on #5: UVB LED

Need to find out the milliwatts of UVB output by LEDs
Need to study the optics – what % of UVB from LED will get to the face (30%?)
Calculate the UVB/vitamin D per 8 hours for type 1 skin
See if that amount of UVB would create any skin damage if used for years
See if the UVB intensity is such that glasses would be required (note: human eye will not see ANY light)
– virtually all glass blocks UVB, no prescription lenses needed
Expect that it can be powered by USB – first guess: LED will use less than 5% of laptop power consumption

See also VitaminDWiki

• Virtually all Chinese teens at 30 degree N have less than 30 ng of vitamin D – Feb 2012

Less than 20 nanograms/ml of vitamin D

• The UK, much further from equator, has a similar problem vs age
  Note: the UK data is % deficiency of 10 nanograms of vitamin D, which is even less than the Chinese 20 nanograms of vitamin D

• Low D in developing countries – less than 5 ng in some children in China – Oct 2010
• Rickets in 30 percent of infants in India who had low vitamin D – March 2011
• 76 percent of young adults in western India had less than 20 ng of vitamin D – Aug 2011
• 70 percent of Koreans in their twenties had less than 20ng of vitamin D – Dec 2010
• Overview Deficiency of vitamin D
• All items: Deficiency of Vitamin D 187 items Feb 2012
• Red Alert – 30% of pre-teens in Tehran had less than 5 ng of vitamin D – Feb 2011
• Every hour of TV watched reduces your lifespan by 22 minutes – Aug 2011 probably the same for multi-media
• Vitamin D statement by Society for Adolescent Health and Medicine – behind paywall July 2013
• Teens increasingly indoors has the following graphs