i get this question in my office everyday and it's such a difficult thing. because i feel like we are fighting a big battle as dermatologists between people who say you need sun for vitamin d and us as dermatologists saying to protect your skin from the sun because of all the harmful effects of sun that we now know without a doubt are the problems. so vitamin d is also available in supplements and typically you can take vitamin d3 at 1 000-2 000 international units per day to get all the vitamin d you need which would be exactly the same as what your skin would make from exposure to the sun. so you really don't need sun exposure. depending on where you live and what your skin color is you might not be able to get enough sun exposure over enough time to keep your vitamin d levels up anyway. so if you think you have a vitamin d deficiency ask your doctor to do a blood test to check your vitamin d levels. if you are low you can take a supplement that will get your levels back up to a range that is normal and effective for you. so that's the way you should get your vitamin d never from the sun as your main source. also you don't have to go out in the sun or to a tanning salon to get that vitamin d just walking around is enough sun over time. sunscreens don't block 100% of the sun's rays so you are getting some vitamin d from the sun and your skin just from going out and about but count on a supplement more than the sun.
i read that you need a some sunshine on your bare skin to get enough vitamin d. so why should i use a sunscreen?