Apparently there is an "answer" but it is dependent on manner factors such as weather, location, skin tone and ability to absorb vitamin D. So, you would consult a doctor I guess to determine optimal exposure. My guess is that a safe bet would be to be outside in the sun for short periods of time at least once a day. By that I don't mean "sunbathing" though. CDC web site has some info.
Cut from Page: "An initial exposure to sunlight (10 -15 minutes) allows adequate time for Vitamin D synthesis and should be followed by application of a sunscreen with an SPF of at least 15 to protect the skin. Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin D."
Yes. We do need vitamin D and the sun is an excellent source. But if you walk to your car in the daytime two to three times (say to work, lunch, and from work) you have received more than enough vitamin D.
In general, you should avoid extended exposure to the sun. As for sun screens, many believe they can be unhealthy because they create a false sense of security. It is called "Risk Compensation" or "Risk Homeostasis". People are MORE likely to stay in the sun longer than they should because they believe the block will protect them. What ends up happening is that people do not appropriately re-apply the lotions on regular intervals or after going in the water. It ends up more people are burned every year.
Slashdot Mirror
Apparently there is an "answer" but it is dependent on manner factors such as weather, location, skin tone and ability to absorb vitamin D. So, you would consult a doctor I guess to determine optimal exposure. My guess is that a safe bet would be to be outside in the sun for short periods of time at least once a day. By that I don't mean "sunbathing" though. CDC web site has some info.
Interesting URL:
http://healthlink.mcw.edu/article/1031002458.html
Cut from Page:
"An initial exposure to sunlight (10 -15 minutes) allows adequate time for Vitamin D synthesis and should be followed by application of a sunscreen with an SPF of at least 15 to protect the skin. Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin D."
Yes. We do need vitamin D and the sun is an excellent source. But if you walk to your car in the daytime two to three times (say to work, lunch, and from work) you have received more than enough vitamin D.
In general, you should avoid extended exposure to the sun. As for sun screens, many believe they can be unhealthy because they create a false sense of security. It is called "Risk Compensation" or "Risk Homeostasis". People are MORE likely to stay in the sun longer than they should because they believe the block will protect them. What ends up happening is that people do not appropriately re-apply the lotions on regular intervals or after going in the water. It ends up more people are burned every year.