Alan, Sydney; Sean Maul, Canada asked:
You have to spend 10-20 minutes in the sun to make vitamin D. Since I moved to Australia Iíve also been told how important it is to wear sun block. My question is, does wearing sun block affect the rate that vitamin D gets formed at? Is there no difference?
Kat - Yes it does. For most healthy people you should be thinking about wearing the sun cream rather than worrying about your vitamin D. The simple reason is this: sun block does block ultraviolet radiation which is the stuff that helps you make vitamin D. Itís also the stuff that damages your skin and gives you skin cancer. This is why in somewhere hot and sunny like Australia itís very highly recommended you protect yourself in that way. You do only need a few minutes of sun exposure to make enough vitamin D. Itís certainly less than the time it takes for your skin to go red or to burn. Itís really hard to be prescriptive about how long you need because itís different for every person. Someone whoís very fair like me, I burn really easily. Iíd probably need much less time in the sun that someone with much darker skin. Also sun block and sun screen are not perfect: theyíre not this magic shield against the sun. People donít use them in the way that manufacturers recommend. They donít put enough on, they donít apply it regularly enough. Youíll know if your skin burns easily that you can put some on and still get burnt. Thereís some ultraviolet getting through. We know there are some studies that show we do need vitamin D to protect us from things like cancer but you can certainly get more than enough vitamin D with casual exposure to the sun: popping to the shops with your sleeves up. If youíre going to go serious exposure to the sun then definitely protect yourself.
Sean Moore asked the Naked Scientists: Hey Chris, I love the show. Only a fool couldn't. Does my body still produce vitamin D if I'm wearing sunscreen? Or does this inhibit it? Blue skies, Sean Moore -Winnipeg, Manitoba, Canada What do you think? Sean Moore , Tue, 8th Jul 2008
Well I found out the hard way.. Iko I just now finished my last dose of vitamin E . They checked me and I am finally caught up enough to stop supplements and she has changed my other meds that prevented me from being unprotected in the sun.. I am now under orders to get at least two 30 minute sessions in the sun a day without sunscreen, if possible.. to help keep my vitamin D up.. I spent 48 weeks of 50,000 units a week, taking it once a week. I can truly say I feel a lot better then I did... which says a lot! Karen W., Sat, 6th Nov 2010