Question: Am I getting enough Vitamin D when I wear sunscreen?
Answer:
The short answer is no. However, even if you didn’t wear sunscreen, you still probably wouldn’t get enough vitamin D.
Vitamin D not only regulates the absorption of calcium and phosphorus, it also helps boost your immune system along with other bodily functions. Your skin manufactures vitamin D when it is exposed to sunlight. However, if you are wearing sunscreen, the protection against the sun prevents your skin from producing vitamin D.
This wouldn’t be so much of a problem if your regular diet supplied enough vitamin D. However, that’s exactly it. Most people don’t get adequate amounts of the vitamin from foods they eat. Coupled with the lack of vitamin D manufactured from sunlight, a deficiency can set in.
Vitamin D deficiency can cause your bones to soften and encourage osteoporosis. It is also linked to liver disease as well as colon cancer. You could stay out in the sun and not wear sunscreen to make sure your skin manufactures vitamin D, however the risks (sun damage, photoaging, skin cancer) far outweigh the benefits. If you did stay out in the sun all day long, you may not even manufacture enough.
Before, people always said that 15 minutes of sun was all it took to get all the vitamin D you needed for the day. However, that is incorrect. The amount of vitamin D your skin produces from sunlight depends on the latitude you’re at, the time of day, and how clothed you are.
I can’t remember the name of the exact study (if I find it, I will post it), but one study found that farmers who worked outside shirtless for the majority of the day, every single day, did not manufacture enough vitamin D. Therefore, even though you can synthesize vitamin D from the sun, it isn't worth not wearing sunscreen because 1) you get sun damage and 2) you don’t make enough of it anyway.
Another way to prevent vitamin D deficiency is to make sure you eat a lot of vitamin D rich food. However, few foods, even fortified milk and orange juice, have enough vitamin D to meet your daily requirements. For adequate intake values, check here.
The only real solution is to take vitamin D supplements, that way you get enough vitamin D without having to tan in the sun. Most people will need around 2000 IU. Supplements are also cheap and easy to find. It's recommended that everyone take a vitamin D supplement because most everyone could use a boost in their vitamin D levels.
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